Geology field trip in the Puget Lowland

updated May 20, 2017



Here is the route we took:

1) Leave Centralia College and head north on State Route (SR) 507 through downtown Centralia up the Skookumchuck River valley toward Tenino. (We may have a optional stop or two near Tenino.)

>>What to look for en route: The Skookumchuck River valley here acted as a glacial spillway. Water draining from the east margin of the Puget Lobe of the Vashon Glacier and from lakes dammed up along its margin gushed through here and into Centralia. Entering Tenino, look left out the van windows to see the Tenino quarry (after we go under the RR underpass and past the espresso stand on the sharp curve to the left).

STOP 1: We pull in to look at the Tenino Sandstone member of the McIntosh Formation, which was quarried here in Tenino and widely used as a building stone. The bank building is located on the SW corner of SR 507 and Olympia St. in Tenino (lat, lon: 46.857220, -122.852678). We will stop there.

>>What to look for: color, grain size, shape, and sorting characteristics, mineral content, and bedding features of the rock. What is your opinion of the Tenino Sandstone as a building stone (strength,?  Were the sediments in the Tenino sandstone deposited by water or wind?

After leaving, either continue northeast on SR 507 (or take Central St.) to Frost St. (south across SR 507 from the main supermarket) and Subway to:

STOP 2: Large boulders at Frost St. and SR 507 in Tenino ( 46.858913, -122.845888).

>>What to look for: Are the boulders on rock type or many? What is the predominant rock type? Are the boulders rounded or angular? What about boulder size? Does the type of rock, size, and roundness tell you about the source of the boulders and the process or processes that moved them here? When was that, and how did it happen?

Head north on SR 507 from Tenino to Yelm. Turn right at the main intersection of SR  507 with SR 510 in Yelm. Go ~0.7 mi to the Safeway. We will stop there briefly.

>>What to look for en route from Tenino to Yelm: The highway is mostly cut through large gravel bars full of cobbles and boulders through here include abundant andesite. These may have been deposited by floods from Glacial Lake Carbon that was dammed up along the east margin of the Puget Lobe ice. We'll see more evidence for this when we cross Tanwax Creek after turning onto SR 7 below.

From the Yelm Safeway head east/north on SR 507 crossing the Nisqually River.  A short distance past the river a the "triangle" intersection, turn right on SR 702 (352nd St. S). We will go about 10 miles east on this road to SR 7, the Mount Rainier Highway.

>>What to look for: Notice the big boulders in the Nisqually River as we cross. Notice that it's very flat at the triangle intersection (46.937991, -122.553888)—We are on top of an ashy lahar deposit from Mount Rainier! Charred trees have been found in the deposit, which varies from about 0.75 m to as much as 2 m thick locally. It has been dated at about 2,500 yr old. Along SR 702 we will be going up and down over the glacially fluted terrain with drumlins.

After we leave Safeway, we will continue north and east, bearing left at the Y-intersection with Bald Hills Rd. and across the Nisqually River, and turn right at the light (~ 0.4 mi) onto SR 702.

>>What to notice: Note the terrace (flat surface) at the intersection of SRs 507 and 702 here. This surface is underlain by a 0.5–2m thick sandy lahar deposit containing pumice and charred wood. The top of this terrace is about 8 m above the river level, but the lahar was probably at least a meter or more deeper than this as it flowed through this area about 2,500 years ago. The lahar was triggered by an explosive eruption of Mount Rainier.

We will go about 10 miles east on SR 702 and turn right on SR 7.

>>What to notice en route: SR 702 goes up and down over southerly-trending smoothed ridges and through "glacially-fluted" topography. This is a landscape that has been modified by the ice. When did that happen?

4) Turn right on SR 7 and head south. 

>>What to look for: About a mile after we turn south onto SR 7 we descend into Tanwax Creek. Notice the large grayish boulders of andesite all over. This valley cuts across the grain of the glacial drumlins. It was cut by a large flood of water and sediment and even a debris flow when Glacial Lake Carbon, to the northeast of here, suddenly breached its ice dam and partially emptied. The andesite boulders and southwest orientation of the valley provided clues to where the flood originated.

We'll continue until we drop into the steep Ohop Valley. Go down to the bottom of the valley where the highway turns left sharply. We will turn around here, come back up the valley a short distance, and safely pull off on the right just before Peterson Road to look a the Mashel Formation of Miocene age.

At the Peterson Road stop, note buried soil layers in the Mashell deposits (46.869859, -122.348457). These deposits consist of floodplain and some lake deposits and contain a lot of pumice and ash similar to what is erupted from Cascade Range volcanoes today. The Mashel Formation is has been dated based on fossils as Middle Miocene. Similar deposits in the Ellensburg Formation have been dated at about 11 million years old.

>>To do: can you comment on the outcrop? We only viewed it from across the highway, but did you seen any bedding or other features?

When you leave this site, it may be easier to drive east on Peterson Road, turn right onto SR 7, and then double back to get to the next stop, which is up the hill from the Mashell outcrop we just looked at. At the top of the hill,  pull of on the right in the lot that is slightly before the sharp turn left.

We will be walking right next to the highway here to get to the outcrop, so please be wary of vehicles and stay off the highway.

>>TO DO: Notice the pits or holes left by rocks that have fallen out of the till matrix. Why do you suppose it the deposit so compact? Notice also the massive texture and poor sorting—very typical of a glacial till. The lahar deposit underneath it has a distinctly different texture.

Next, turn right on SR 7 and head north. After ~ 1 mi turn right on Stringtown Road. When you get to Eatonville Cutoff Road, turn right, go a short distance, and then turn left on SR 161. We will head north on SR 161 to Kapowsin Road (~4–5 mi?). [An alternative to this route is that we may go up the Ohop Valley instead in order to get to Electron (below).

>>TO DO: Look for more andesite boulders from the "Tanwax flood" en route.

Turn right on Kapowsin Road and continue east through the small hamlet of Kapowsin. After the intersection, Kapowsin Road becomes Orville Road, continue about 0.75 mi and turn into the boat launch at Lake Kapowsin.

(46.984474, -122.218528). [we skipped this stop in 2017]

>>TO DO:  Walk out on the walkway adjacent to the boat launch. Do you see any submerged tree stumps in the lake? What's going on here—Why would a lake contain submerge trees? What created the lake? About when did this happen? Why are there no trees sticking up above the level of the lake?

After leaving the boat launch area at Lake Kapowsin, turn right onto Orville Road and continue to the north for about 0.9 mi. We will

At Electron we will turn right on Electron Road (gravel) and then make an immediate left on the access road, parking off to the right side.

(46.995745, -122.192588) NOTE: truck traffic from the quarry near here can be heavy, so be careful at this stop and when leaving!

>>What to look for. Notice the consistency of the sandy matrix of the clay-rich Electron Mudflow deposit as well as the sorting (well sorted or poorly sorted?) and roundness vs. angularity of the cobbles in the deposit--which is it? What are the cobbles made of? Break a few and examine them. Lake Kapowsin is dammed by the Electron Mudflow and contains a submerged forest. How thick is this deposit here? Where didi it originate and how? How far did it flow? What is the significance of studying such deposits?

Next get back out onto Orville Road and go right (north) toward Orting. At SR 162 intersection, we go left into Orting. We will stop for lunch at the Safeway, which is slightly north of town on the left.

To get to the next stop, go north on SR 162 and turn left into  the Whitehawk Development at Whitehawk Rd. For optimal parking, pull in and park along Corrin Ave.; then walk north on Whitehawk Blvd.


a) Large volcanic breccia boulder (47.102349, -122.214924). What is the significance of this boulder? Where did it come from, and how did it get here. What is your evidence for this?

b) Subfossil tree stump in stormwater pond (47.103281, -122.214525). Why is there a tree stump rooted in the stormwater pond? What killed the tree, and when?

If there is no time for the optional trip to Enumclaw, go south retracing your general route along STR 161 and over to SR 702 to get back to Yelm. After Yelm, continue toward Olympia on SR 510. Take Interstate HWY 5 (I-5) south to the downtown Olympia, Exit 105(?) and take the right hand fork toward Plum Street and the Port of Olympia. Head north on Plum Street and continue as it becomes East Bay Road all the way to Burfoot County Park. The entry is difficult to see, but is a left turn about 0.9 mi north of Zangle Road. Pull into the park and head toward the far west parking area near the restroom. The main trailhead to the beach is south of the parking area.

STOP 8: BURFOOT COUNTY PARK (47.132422, -122.901423): [We did not go to this stop—the tides weren't low enough. Instead we went to Mud Mountain Dam below]
>>TO DO: hike down to the beach at low tide. Vashon glacial till outcrops near the top of the terrace. What kind of deposits are visible along the bluffs? If you can, draw a sketch of the outcrop. What kinds of beds are visible  at the beach? What is the interpretation of the origin of the deposits?

option B: Go to Enumclaw first: turn right off Orville Road onto SR 162  and head northeast toward Buckley. The town of South Prairie is a speed trap, be careful. At the 30 way intersection that turns off to Mount Rainier, go left toward Buckley. When you come to a stop sign, make a short left and merge right onto SR 410 to continue east through Buckley and across the White River to Enumclaw. We will continue in Enumclaw stopping at the Safeway on the right hand side of the highway (unless we first stop in Orting).

9) To get to Mud Mountain Dam, continue east on SR 410 going up up up to the top of the plateau. After a few miles you will pass a large quarry on the left and then slighty after that will see the entrance to Mud Mountain Dam on the right. Turn in.

>>What to look for: The plateau surface here consists of the great Osceola Mudflow (5,600 yrs old) from Mount Rainier. You may see some evidence for mounds.

10) Not sure if the park is open, but we will continue straight in hoping that it is. If so, we'll stop at the rest rooms. there and walk over to the viewpoint.

>>If the viewpoint is open, we should be able to see the dam and also read the interpretive signs.

11) After going to the viewpoint, we will drive back to the highway, stopping at a gravel parking area on the right. We will park here for our hike to the bottom of the canyon.

>>What to look for: Osceola Mudflow at top. After first descent to a flat area, note gravelly deposits at left just before the road drops again. This is a post-Osceola Mudflow gravel derived from a Mount Rainier lahar. At the canyon bottom we will see glacial lake deposits and also a stack of post Osceola lahar-derived layers with fascinating features to interpret. This outcrop was featured on the Discovery Channel.

12) Return via the same route toward Yelm. If we have time we will stop at selected sites near Tenino on our return trip.

>>One option is to stop at Offut Lake, another is go to the Mima Mounds; still another would be to head up the Skookumchuck River to the dam where you can see ~38 Ma lavas of the Northcraft Formation.


9. Burfoot Park (sketch and interpret) At the beach we will see several fascinating exposures of glacial and interglacial deposits. Draw a cross section that depicts and describes the layers—provide scale. What is the nature of the lavender colored sand? Sketch and describe the layers and types of rocks you find on the beach (at least 10). END! 

2ND Optional stop.. I-5 south to the Littlerock exit. West to the T-intersection ~3.7 mi, then right a short distance to Mima Mounds State Preserve. (DNR quarry is accessed by going left at this intersection and heading south about 1.2 mi and then heading ¼ mi west on Bourdeaux Rd. There mounds can be seen in cross section. Sketch and interpret if we go there.


1)      Possible outcrops of Eocene Skookumchuck sedimentary rocks in Centralia (same formation as in coal mine).

2)      Go north on SR (State Route) 507 from downtown Centralia (Tower Street). Slightly north of Bucoda turn right on Skookumchuck River Road and go several miles to bedrock outcrops of the Northcraft Formation volcanic rocks and large boulders of (Mount Rainier?) Andesite sitting on the valley floor.

3)      Backtrack and go north to Tenino via Johnson Creek Road or SR 507 at Bucoda.

4)      At Tenino see Tenino Sandstone of McIntosh Formation and boulders of Mount Rainier Andesite.

5)      OPTIONAL: Go to Offut Lake Park (note Mima Mounds en route and in vicinity), and then north old SR 99 and right on Waldrick Road to Military Road. Right on Military Road to SR 507. North on SR 507 to Yelm.

6)      Note cobbles, boulders, and large bar-like landforms along SR 507 on the way to Yelm. Implications???

7)      At Yelm join w/ SR 510 and turn right at the main intersection. Cross Nisqually River and head east on SR 702. Note glacial fluting and drumlinoidal hills en route. The road goes up and over these landforms.

8)      South on SR 7 to bottom of Ohop Valley (note light gray-to-white Miocene river and lake deposits and volcaniclastic sediments exposed in valley wall). Turn around on the street at right at the valley bottom, and drive back up the valley wall pulling off to the right at the very top. Note glacial till over Mount Rainier Dmm exposed at the top of the grade. This is a dangerous stretch of road. If we walk south a bit to the outcrop be very wary of traffic coming up the hill).

9)      Head north on SR 7 and turn right at the Eatonville Cutoff Road. At SR 161 go north to Kapowsin Road. There go east (left) and keep going until you descend past Lake Kapowsin into the town of Electron. There we will turn to the right to see an outcrop of the Electron Mudflow from Mount Rainier.

10)   Go north on the road toward Orting. At the junction of SR 162 turn left and go into Orting. We will have a break at the Safeway slightly north of town.

11)   Next stop: Ptarmigan Middle School on the left side of SR 162 north of Orting. Note subfossil trees on lawn in front of school. These stumps were pulled up from below ground.


13)  OPTIONAL STOP: Huge cross beds of course gravel exposed along Reservation Road west of Yelm.

14)  OPTIONAL STOP: subfossil trees in Red Salmon Creek or in Woodward Creek.

15)  OPTIONAL STOP:     Burfoot Park.

16)  OPTIOANL STOP:     Mima Mounds


Continental glaciations dramatically sculpted the landscape of the Puget Lowland between about 22,000 and 15,000 years ago. The Puget Lobe of the continental ice sheet reached to south of Olympia. Rivers draining the southern Washington Cascade Range were shunted around the toe of this lobe, merged with meltwater from the glacier, and flowed out via the Black Lake spillway, near South Puget Sound Community College, and out to the Pacific Ocean by way of the Chehalis River valley.  Postglacial erosion and deposition has continued to alter the landscape. We will see evidence of glacial and interglacial processes during our trip.

Today we will travel north through the Puget Lowland to see features and deposits that resulted from glaciation-related processes and to look for evidence of the past activity of Mount Rainier. We will also stop at outcrops of bedrock.

Tentative Field stop plan: Leave Centralia College, go downtown and then NORTH on Tower St. and follow State Route 507 (SR 507) north. About 1.5 mi north of Bucoda near the Frost Prairie Store turn right on ?SkookumChuck Road. We will head east several miles to Stop 1. Go back to SR 507 and head north into Tenino.

Stop 2 is at Dave’s Market to look at the Tenino Sandstone (stone grocery bag sculpture) and boulders on the southeast side of SR 507.

Leave market and go north toward Olympia on old Highway 99. After about 3 miles turn right on Offut Lake Road. After a mile and ¼ or so turn left at the Offutt Lake Sign and park near the Offutt Lake Market. Stop 3.

Go back to HWY 99 and turn right. Go north ~1.5 mi past Mima Mounds to Waldrick Road and turn right. Keep going 6 – 7 mi and turn right on Military Road. Go back across Deschutes River past McIntosh Lake. Carefully turn left onto SR 597 and head to Yelm. At Yelm, turn right onto SR 510. Keep going straight through at Five Corners (Chevron) and cross the Nisqually River. At the Y turn right onto SR 702. Go 10 mi east to SR 7. Turn right. Head south. When we descend into the Ohop Valley past buff-to-gray sediments on the right—this is the Miocene Mashel Formaton. We will go back to the top of the hill to look at deposits exposed there.

Stop 4. Carefully get back on the highway and go north less than 2 miles to Stringtown Road—turn right and go several mi turning right on Eatonville Cutoff Road. After a short distance carefully turn left and go north on SR 161. After about 6 mi, turn right on 304 ST. E and head toward Kapowsin. At the junction (Orting Kapowsin HWY) go straight past Lake Kapowsin (right) and pull off to the right on the gravel road past the creek at Electron:

Stop 5. Leave stop 5 and continue north. Carefully turn left at SR 162 and head into Orting. Stay on the main road as it winds through town and turn left into the Safeway complex for a break.

Stop 6 is Ptarmigan Middle School, ~1/2 mi north of town on the left. Leave school and carefully turn left. Go north ~ 7 mi nearly to Sumner and turn right on SR 410. Follow SR 410 all the through Buckley and Enumclaw. Go east 4 to 5 mi and turn right at Mud Mountain Dam.

Stop 7: Restrooms may be open at the viewpoint (~2 mi in) however note the big parking area on the left ~ ¾ mi in from SR 410. This is where we will park for our hike into the canyon after visiting the viewpoint. Return to Olympia via SR410, 512, and I-5 going through Puyallup.

While driving on Pacific Highway SW we will pass through Violet Prairie, which in many areas is covered by Mima Mounds. The Mima Mounds are one of geology’s mysteries that have never been convincingly explained. What could have caused these mounds?

1. At the conclusion of this trip, search in the library and on the internet and find at least three sources of information on the Mima Mounds. An important library resource is    What did you find out?  Remember to list the citations you found. Ask you instructor for hints on where and how to search for this information. In your field notebook draw a sketch of the mounds and make a few observations about their dimensions, spacing, etc. Speculate on how you think they might have been formed.

If we stop at the Mima Mounds, note the size range, shape, and sorting of sediments in the mounds. Also note their overall size, shape, and distribution. We will get another look at the Mima Mounds if we visit the Mima Prairie Natural Resource Conservation Area managed by the WADNR.

At the junction of State Route (SR) 507, continue north through Tenino making sure you are going the speed limit! At Pacific Highway  urn left into the parking lot at Dave’s Grocery store.

You have probably noticed some of the sandstone buildings as you passed through Tenino. The Tenino quarry is near here, and was a source of sandstone for the old State Capitol building in Olympia, the Thurston County Courthouse, and other structures. In the parking area is the sculpture of a grocery bag in Tenino Sandstone. We will look at the grocery bag to describe the texture of the sandstone and any other features.

2. Describe the sandstone here according to the size and mineralogy of the grains and sorting.

Notice the boulders across SR 507 from the grocery. Tenino is littered with boulders like this. Many are composed of andesite rock, the kind that originated at Mount Rainier. Are the boulders rounded or angular? What kind of processes could have carried these boulders here?

Depart the grocery and head toward Olympia on Old 99, Pacific HWY SE. Turn on Offutt Lake Road and follow the signs to Offutt Lake. We will park at the Offutt Lake store and walk a short distance to the lake.

3. At Offutt Lake boat launch area notice the many boulders? Closely examine the boulders in the fireplace area or nearby. What do you notice about their texture? How would you describe this?  Are the boulders diverse in rock type or do they look like they are of a similar rock type?

After returning to Offutt Lake Road, turn right go back to OldHWY 99 and go north to Waldrick Road. Turn right and follow the Deschutes River upstream to Military Road SE and turn right, crossing the valley of the Deschutes River.

4. Notice the large rounded gravel bar on the “left side” of the river valley. (“river left means on the left side as you look downstream). Can you see any evidence of the size of the particles making up this bar?   What about the overall size of the bar? Does that provide a clue to the hydraulics and discharge of the flow that deposited it?

After this trip, consult the recently completed geologic map of SE Olympia (GM-56) by Robert Logan and Timothy Walsh to learn more about the geologic history of this area. What do you notice about the many terraces they mapped? This map will be in the library and is also available online under “Publications” at   

Continue in a SE direction on Military Road to SR 507. At the highway, carefully turn left and head toward Yelm via Rainier, making sure to go the speed limit. Note any boulder fields or other features you see along the way.

5. Between Rainier and Yelm, note the undulating terrain? Note the sediment make up. Could these features be large bars? What is the approximate spacing of the features?

At Yelm, turn right on 507/510 and continue over the Nisqually River, which heads on Mount Rainier. Turn right on SR 702 and head east to SR 7.

Note the flat terrace at the intersection of 507 and 702. Terraces can record a river’s history. This terrace is veneered by a sand derived from a lahar from Mount Rainier. This “lahar runout” is the diluted flood from a lahar, a far-traveling volcanic debris flow. Sandy lahar-derived flows such as this one are commonly triggered by eruptions that melt snow and ice. The age of this deposit is estimated to be about 2,450 yr. B.P., and its sediments have been found in the Nisqually River delta. Thus, the volcanic flood flowed all the way from Mount Rainier to Puget Sound.

Continuing east, the road goes up and down over N-S-oriented elongate ridges the are interspaced with parallel valleys or “flutes”. This is classic glacially sculpted terrain. The hills are drumlins, or streamlined molded ridges formed by the movement of glacial ice over sediments. The orientation of the axes of the ridges shows the direction of movement of glacial ice.

At SR 7, turn right and go south on SR 7. The road descends into the Tanwax Creek valley, which was cut into glacial deposits by great floods of water. .

Note the boulders in this area. These large boulders are mostly andesites, and the Tanwax valley connects with the network of valleys downstream that contain andesite boulders. This is evidently the pathway of a large flood at the end of the Ice Age. The flood originated with lakes that were dammed up by the ice along its margin.

Stop 4. is at the top of the hill along the SR 7.

We will very carefully walk along the edge of the highway a short distance to see the deposits on the west side. DO NOT CROSS THE HIGHWAY. KEEP A SAFE DISTANCE OFF THE ROAD AND WE WARY OF TRAFFIC. Sketch the outcrop here and describe the deposits. Note clast size, shape, and sorting. Speculate on what type of natural process might leave these deposits. The uppermost two layers, here and several others below are Pleistocene in age. Below these deposits much of the exposed material in the gray outcrops along the road is the Miocene age Mashel Formation, which mostly consist of material deposited in river valleys and lakes and which are full of pumice and dacite fragments similar to the type of lava being erupted by Mount St. Helens today.

Carefully get back on the highway and go north less than 2 miles to Stringtown Road—turn right and go several mi turning right on Eatonville Cutoff Road. After a short distance carefully turn left and go north on SR 161. After about 6 mi, turn right on 304 ST. E and head toward Kapowsin. At the junction (Orting Kapowsin HWY) go straight past Lake Kapowsin (right) and pull off to the right on the gravel road past the creek at Electron: Stop 5.

6. Lake Kapowsin contains a submerged forest. The lake was formed about 500 yrs ago when it was dammed by the Electron Mudflow from Mount Rainier. The Electron Mudflow was named for the town of Electron, where US Geological Survey geologist Dwight “Rocky” Crandell found a log in it that he dated using radiocarbon. We might stop quickly here to examine the mudflow deposit. Describe the sorting of the sediment. Can you tell how much clay it contains? Explain.

Proceeding north on Orville Road, we will pass an outcrop of the Orting Drift, the oldest known glacial deposit in the Puget Lowland. We continue north across the Puyallup River bridge and the valley widens as we approach Orting.

7. Notice the overall convex shape of the valley bottom here. The entire valley is covered by the Electron Mudflow, which has a depth of more than 20 ft. here. Crandell measured one large boulder the mudflow had carried down at 32 ft in length! What does clast size imply?

Turn left on SR 162 and continue to Orting –go the speed limit. We can stop in town for coffee or restrooms. Pull into the north end of the Safeway Parking lot on the left where we will have a short break.. After the break, we will go a short distance north and turn left into the parking lot at Ptarmigan Middle School.

Here we will see some large remnants of the subfossil trees that were found beneath the ground. The trees, which were buried by the Electron Mudflow, were rooted about 16 ft below the surface. Geologists estimated that the lahar reached here from Mount Rainier, about 30 miles flow distance, in about one hour or less.

8. What are the implications of future similar events? Sketch a cross section that shows rooted trees 16 ft below the surface. Why are none of the trees protruding above the surface today?

Option: We may continue to Mud Mountain Dam. If not continue north from the school on SR 162. We will take a left on Military Road and go up the hill continuing over to SR 161 (Meridian) Turn right and go north to SR 512. Take SR 512 to the east to I-5. Take I-5 south and get off at the exit 105-B. Continue north; we well follow East Bay Drive nearly all the way to Burfoot Park.


Crandell, D. R., 1963, Surficial geology and geomorphology of the Lake Tapps quadrangle, Washington: U.S. Geological Survey Professional Paper 388-A, 84 p., 2 plates. [Accessed at​​bs/pp/pp388A ]

Crandell, D. R., 1971, Postglacial lahars from Mount Rainier volcano, Washington: U.S. Geological Survey Professional Paper 677, 75 p., 3 plates.​​bs/pp/pp1444

Dragovich, Joe D.; Pringle, Patrick T.; Walsh, Timothy J., 1994, Extent and geometry of the mid-Holocene Osceola mudflow in the Puget Lowland--Implications for Holocene sedimentation and paleogeography: Washington Geology, v. 22, no. 3, p. 3-26. [accessed on October 11, 2010 at]

Goldstein, B.S.; Pringle, Patrick; Parker, B.  Futornick, Z. O. 2010, Tracking the late-glacial outburst flood from glacial Lake Carbon, Washington State, USA [abstract]: Northwest Scientific Association, Annual Meeting, 82nd, p. 65. [Accessed abstract on March 28, 2010 at and poster on April 20, 2010 at]

Pringle, Patrick T., 2008, Roadside geology of Mount Rainier National Park and vicinity: Washington Division of Geology and Earth Resources Information Circular 107, 191 p. [Accessed on June 22, 2008 at ]

Walters, K. L.; Kimmel, G. E., 1968, Ground-water occurrence and stratigraphy of unconsolidated deposits, central Pierce County, Washington: Washington Department of Water Resources Water-Supply Bulletin 22, 428 p., 3 plates. http://www.ecy.​​/eap/wsb/wsb_Al​l.html ]