GO PLACES! DO THINGS!

Along the ICE AGE FLOODS
NATIONAL GEOLOGIC TRAIL


The Ice Age Floods National Geologic Trail covers some 16,000 square miles (41,440 km2) in present day Montana, Idaho, Washington, and Oregon. We have hand picked some of the best of the best places along the Trail and present them here for you enjoy and explore! Check back often, we will be adding new and wonderful destinations for your entire Family to enjoy!

MONTANAIDAHOWASHINGTONOREGON

SOME PLACES TO GO and THINGS TO DO in MONTANA

Glacial Lake Missoula National Natural Landmark

Glacial Lake Missoula National Natural Landmark Ice Age Floods National Geologic Trail Glacial Lake Missoula was the largest of several lakes impounded by the Cordilleran Ice Sheet in the Northern Rocky Mountains during the Quaternary period. The lake was approximately 2,900 square miles in size and contained more than 500 cubic miles of water. It occupied the Mission, Jocko and Little Bitterroot valleys, drained by the Flathead River; and the Missoula, Ninemile and Bitterroot valleys, drained by the Clark Fork River. The lake was formed by an ice dam across the mouth of the Clark Fork River at Lake Pend Oreille, Idaho, a result of successive advances of a lobe of the Cordilleran Ice Sheet. The site is located 12 miles north of Perma, Montana.At least three and possibly more than 100 separate collapses of the ice dam, possibly coincident with periods of ice retreat, caused the lake to drain, producing catastrophic floods across the Columbia Plateau and down the Columbia River Basin. It is estimated that the waters of Glacial Lake Missoula, 1,000 feet deep at Eddy Narrows, were withdrawn at a peak discharge rate of 10 cubic miles per hour. Approximately 550 cubic miles of water passed through those narrows during withdrawal. Evidence of this catastrophic withdrawal can be found in scourings, high eddy deposits of flood debris, flood bars of boulders and course gravel, and successions of giant arcuate ripples or ridges of gravel resting on bedrock surfaces. Ripples appear as ridges 15 to 50 feet high, 100 to 250 feet wide, and from 300 feet to a half-mile long. While the form, structure and arrangement of these features are similar to that of ordinary current ripple marks, they are termed giant flood ripples, due to their large size. The giant flood ripples at this site are unusual due to their being on the down-current side of notches in a ridge separating two basins that were both subsidiary to the main course of Lake Missoula in the Clark Fork Valley. The best examples of giant flood ripples are found in Camas Prairie. Quick Facts Designation:National Natural Landmark OPEN TO PUBLIC:Private Land, closed to the public, but features throughout the area are visible from many vantage points.

Read More »

Montana Natural History Center

Montana Natural History Center Ice Age Floods National Geologic Trail  The mission of the Montana Natural History Center is to promote and cultivate the appreciation, understanding, and stewardship of nature through education. Founded in 1991, MNHC was the brainchild of a group of educators who were involved in various efforts to educate both kids and adults about the natural history of western Montana, and who decided to unite those efforts into one environmental education organization. MNHC provides nature education programming for people of all ages through summer camps, kids’ activities, Visiting Naturalist in the Schools, Master Naturalist certification courses and Field Days, evening programs, Field Notes on Montana Public Radio, museum tours, and more.  We have a variety of exhibits that focus on the flora, fauna, geology, and ecology of our beautiful state. Please stop by and visit! MNHC often partners with the Ice Age Floods Institute to share fields trips and lectures about the Ice Age Floods.   MNHC has exhibits that help visitors explore the Glacial Lake Missoula and Ice Age Floods. Learn more at:Explore Glacial Lake Missoula | Montana Natural History Center (montananaturalist.org) The Glacial Lake Missoula Chapeter of the Ice Age Floods Institue also produced a short movie about Glacial Lake Missoula. You can find a link here. Quick Facts Location:120 Hickory Street, Suite A, Missoula, Montana

Read More »

Little Money Creek Gulch Fill

Mounds of soil, sand, gravel, and other coarse materials covered with light vegetation can be seen in the side gulches all along the Flathead River where tributaries drained into what was Glacial Lake Missoula.  They were deposited by currents eddying into the slower water in these gulches and also by the drop in velocity of the streams carrying deposits from higher elevations on the far side of the river along the path of the escaping floodwaters.  The flow of floodwaters through this narrow valley was estimated by J.T. Pardee at between 8 and 10 cubic miles per hours – more than the combined flow of all modern rivers in the world.  Similar gulch fill can be seen in many locations along this beautiful stretch of the river, which today generally flows smoothly and looks completely flat. There are numerous pull-outs along MT 200 between Perma and Paradise; the view pictured here is at mile marker 91.

Read More »
SOME PLACES TO GO and THINGS TO DO in IDAHO

Must See Floods Features in Northern Idaho

SOME LOCAL NORTHERN IDAHO ICE AGE FLOODS and GLACIAL FEATURES Purcell Trench – This structurally formed valley became the passageway for the Purcell Ice Lobe that divided into five glacial sub-lobes.  The east moving sub-lobe blocked the Clark Fork River forming Glacial Lake Missoula, the source of the Ice Age Flood waters.  Other sub-lobes modified and deepened the basin now occupied by Lake Pend Oreille or helped define several important N-S transportation routes. The Purcell Trench is visible from City Beach in Sandpoint and Schweitzer Mountain Rd.  Hwy 95 follows the Purcell Trench from Sandpoint to beyond Bonners Ferry. Cabinet Gorge – Contact of Pleistocene Ice and Glacial Lake Missoula Water – Although the contact of the Pleistocene Ice and the lapping waters of Glacial Lake Missoula was in flux as the glacier advanced and retreated, the Cabinet Gorge is considered by many to be a likely location of the terminus of the Clark Fork sub-lobe that blocked the drainage of the Clark Fork River.   Evidence of glacial erosion and till deposits indicate glaciation; however, flood deposits on the south side of the river attest to Ice Age flooding.  Cores taken during the construction of the Cabinet Gorge Dam suggest multiple stages and events of ice damming. An AVISTA maintained viewpoint at the Cabinet Gorge Dam with Ice Age Floods signage provides an excellent location to ponder the formation and disintegration of the ice plug blocking the Clark Fork River.  Glacial Striations – Striations can be viewed along Hwy 200 east of Hope and on the south side of Castle Rock east of Clark Fork. Glacial/Flood Related Erratics – Large and small erratics cover the glacial and flood modified landscape.  Large erratics can be seen along Hwy 200 east of Clark Fork, in Sandpoint’s City Beach and in Farragut State Park.  A large pile of erratics excavated from flood deposits are visible on the west-side of Hwy 95 south of the Hoodoo Channel.  A giant ice-rafted flood related erratic weighing over 1,600 tons is located on the east-side of Hwy 41 near Twin Lakes.  Lake Pend Oreille – Cross-section morphology, depth, and sediments – This is where it all started! Lake Pend Oreille is the largest lake in Idaho and the deepest lake in the Pacific Northwest and the 5th deepest in the US. The lake level is 2062 ft above sea level with depths over 1,000 feet and an additional layer of over 1,500 feet of glacial-fluvial deposits going to bedrock, with the surrounding terrain as high as 6002 ft. The glacially modified U-shaped bedrock valley, cut to approximately 600 feet below sea level, was formed by the Pend Oreille glacial sub-lobe. This glacial sub-lobe was up to 4,000+ ft. thick and 30+ miles wide. It was the ice plug responsible for blocking the Clark Fork River. It collapsed catastrophically as often as about every 10-60 years, releasing 40-100 Ice Age Floods.  The location of the lake is probably related to an old river valley controlled by faults. The Lake Pend Oreille basin was carved by the repeated advances of Pleistocene ice and scoured by ice age floods. With the waning of ice age flood waters, the basin was, and continues to be, filled with glacial outwash and flood deposits. The lake is dammed at the south end by thick glacial and flood deposits the mark the beginning of the “Outburst Deposits”. There is a pullout on Hwy 200 approximately one mile west of Hope with signage already established that provides a great view looking south across Lake Pend Oreille to the Green Monarch Mts. Another view of the former ice plug location along Hwy 200 is the mouth of the Clark Fork River at the Clark Fork Drift Yard. Giant Current Dunes or MegaRipple Marks – One of Bretz’ most important pieces of evidence for catastrophic flooding was the “giant current dunes.” These large-scale bedforms appeared as patterns of parallel ridges and swales on many aerial photographs in the flood channels in the scabland of Washington, but had escaped recognition from the ground because of their size. Giant Current Dunes are visible west of Clark Fork near Castle Rock; however, the most prominent and visible Giant Current Dunes are located several miles east of Spirit Lake along Hwy 54 where the highway cuts through the dunes showing their undulating profile. The location of many of the telephone poles on the crest of these dunes accentuates these landforms. The dunes form transverse to the current direction, and form cusps that are convex upstream, with arms that point downstream. Furthermore, the size of the cusps appears to decrease in the direction of lower velocity. Internally, the dunes consist of gravel and pebble foresets. Giant current dunes exhibit an asymmetrical profile with the downstream (lee) slope steeper than the upstream slope. Crests range from 20 to 200m apart and heights range from 1 to 15m (Baker and Nummedal, 1978) and are among the largest measured throughout the Floods area. The Spirit Lake current dunes can also be easily recognized from the air by their characteristic pattern, accentuated by vegetation. This dune field is immediately in the path of the breakout from Lake Pend Oreille, and experienced some of the highest energy flows. Rhythmites – Rhythmites are glaciolacustrine sediments associated with flood events and are useful in attempting to determine the number of Ice Age Floods.  A 112-foot cross-section of rhythmites is located at the junction of East Fork Creek and Lightning Creek approximately 6.5 miles northeast of Clark Fork along Lightning Creek Road (NF-419). Proglacial Deposits – This type of deposit is found associated with most of the drainages on the south side of the Clark Fork Valley and extend from the mouth of the Clark Fork River to nearly Thompson Falls in Montana.  These sediments are glacio-fluvial deposits deposited in contact with the ice and therefore provide evidence of glaciation in the Clark Fork River drainage.  The associated geomorphic features formed by these deposits are referred to as “kame deltas”. The gravel pit associated with Dry Creek (approximately 8 miles west of Clark Fork

Read More »

Farragut State Park

Farragut State Park Ice Age Floods National Geologic Trail Farragut State Park is located at the “breakout” of Glacial Lake Missoula floods, where the ice dam in the Clark Fork valley and the 20-mile-long tongue of ice occupying the Lake Pend Oreille basin failed. From there, a torrent of water and ice burst from the south end of the lake. Farragut State Park is located at the “breakout” of Glacial Lake Missoula floods. Failure of the ice dam in the Clark Fork valley fractured and broke apart the 20-mile-long tongue of ice occupying the Lake Pend Oreille basin, and a torrent of water and ice burst from the south end of the lake. That churning slurry of flood waters, ice, boulders and other debris erupted from the south end of Lake Pend Oreille, flowing 2000 ft deep across Farragut State Park. Nearly all of the water escaping from Glacial Lake Missoula passed through this area. Discharge estimates range from 14 to 21 million cubic meters per second! Vic Baker’s definition of a megaflood is one which has a discharge of at least 1mil cubic m/s, so we are possibly looking at ground zero for the worst Pleistocene flood in the world. Farragut State Park includes many geologic features left by glaciation and megafoods.Hoodoo channel, an abandoned outlet of Lake Pend Oreille provided a pathway for late-glacial meltwater and for the last outbursts from Glacial Lake Missoula. The channel is marked with a number of closed depressions, probably the result of melting icebergs. One of the largest of these features have been proposed, including kettles, potholes, and sub-glacial meltwater. Some of that debris was deposited to form the Rathdrum Prairie Outburst Plain, an extensive, heterogeneous mix of flood deposits. Farragut State Park offers unique scenery, history and an abundance of recreational opportunities. Quick Facts Location:13550 E. Hwy 54 Athol, ID 83801 

Read More »

Green Monarch Ridge

Green Monarch Ridge Ice Age Floods National Geologic Trail THIS IS WHERE IT ALL BEGAN! The Green Monarch Ridge viewpoint, just south of the Hope Fault, is positioned along the edge of the Purcell Trench Ice Lobe. Here it was responsible for damming the mouth of the Clark Fork drainage basin. This damming effect resulted in the formation of Glacial Lake Missoula, the source of the waters for much of  the PNW Pleistocene Ice Age Floods. The Purcell Trench Ice Lobe originated in Canada and flowed south into Idaho, guided by the structural control of the Purcell Trench. Following the path of least resistance into the basin now occupied by Lake Pend Oreille, it was impeded by the Green Monarch Ridge, located approximately 10 miles south of this viewpoint. Grinding and scraping, the Purcell Trench Ice Lobe backed up behind the Green Monarch Ridge, eventually building an ice plug up to 4,000 feet thick, and scouring out the deepest parts of Lake Pend Oreille. The Purcell Trench Ice Lobe divided into four sub-lobes: one went approximately west (US Highway 2), two went south (US Highway 95 and Lake Pend Oreille) and one went east (SR 200). All four sub-lobes contributed to blocking the Clark Fork drainageQuick Facts MANAGED BY:US Forest Service – Idaho Panhandle National Forest

Read More »
SOME PLACES TO GO and THINGS TO DO in WASHINGTON

Drumheller Channels National Natural Landmark

Drumheller Channels National Natural Landmark Ice Age Floods National Geologic Trail The Drumheller Channels are unique because no single channel or major cataracts were formed. The Drumheller Channels are the most spectacular example in the Columbia Plateau of basalt “butte-and-basin” channeled scablands. This is an

Read More »

Scooteney Reservoir

Scooteney Reservoir Ice Age Floods National Geologic Trail Situated about nine miles southeast of Othello, west of Highway SR-17, this body of water has a year-round open fishing season. Smallmouth Bass, Largemouth Bass, Walleye, Bluegill sunfish, crappie, and Yellow Perch produce good action throughout the

Read More »
SOME PLACES TO GO and THINGS TO DO in OREGON

Columbia Gorge Discovery Center & Museum

Columbia Gorge Discovery Center & Museum Ice Age Floods National Geologic Trail, Lewis & Clark National Historic Trail, Oregon National Historic Trail The Columbia Gorge Discovery Center & Museum is located on a 54-acre point of land adjacent to the Columbia River and is the

Read More »

Willamette Floodplain National Natural Landmark

Willamette Floodplain National Natural Landmark Ice Age Floods National Geologic Trail The Willamette Floodplain represents the mix of bottom-land grasslands once common throughout the interior valleys of western Oregon and Washington. It is a large remnant example of largely un-plowed native grassland and ash woodland.

Read More »

Museum of Natural History, University of Oregon

Museum of Natural and Cultural History, University of Oregon The museum offers a variety of seasonal and year-round programs for science and culture enthusiasts of every age. Delve into Oregon’s story, from the archaeology of the First Americans to the dynamic cultures of today’s Tribes.

Read More »
Even MORE PLACES TO GO and THINGS TO DO

Click a STATE for MORE PLACES TO GO and THINGS TO DO

MONTANAIDAHOWASHINGTONOREGON