Intermountain Region

From Highway 191, just north of Jackson, WY, take the Gros Ventre Road past the town of Kelly to the Gros Ventre Overlook. If you are coming from the north, take Antelope Flat Road, then head south on Kelly Road to Gros Ventre Road.

In 1925, prolonged rainfall made the hill slope substantially unstable creating a large slide that formed a dam 225 feet high. It was estimated that about fifty million cubic yards of rock material moved. Almost two years later, the dam failed and practically destroyed the town of Kelly moving mud, rock, rubble, and water in a torrential push downstream. The slide area can be seen from many miles away as you approach the canyon and an interpretive trail, signs, and overlook are located at the slide area. Large boulders and rubble fill the canyon below Lower Slide Lake.

Geologically speaking, the mountains in this area are relatively young and still quite active. Earthquakes can be felt throughout the year as evidenced by many small slumps present, but none as catastrophic as the Gros Ventre Slide.

From I-70, exit at the town of Elsinore just south of Richfield, UT. Head east towards the town of Nibley and then turn south on State Highway 118 towards Monroe. Continue on State Highway 118 as it veers southeast and turns into Forest Road 078.

Flood deposits seen along the walls of Pole Canyon attest to the dramatic volcanic history behind the formation of Monroe Mountain. About 25 million years ago, two volcanic centers, near Signal Peak and Langdon Mountain, violently erupted clouds of volcanic ash, dust, and smoke to produce localized thunderstorms. Torrential floods cascaded down the newly formed volcanic flanks carrying boulders and debris. Since large amounts of material had been removed from the magma chamber creating a large void, the overlying material collapsed and formed the Monroe Peak Caldera measuring about 14 by 11 miles.

A quiet period of erosion and meandering streams ensued from 14 to 7 million years ago. The Sevier River Formation is the result of sediments deposited in channels, swamps, and lakes.

Earthquake activity beginning about five million years ago led to the lifting and bending of large blocks of crust, including Monroe Mountain. Valley floors dropped while mountain slopes lifted. The repeated shaking and slope instability generated many landslides (Thompson Creek Landslide near Monroe, Elbow Landslide near Marysvale, and the Brink near Burrville).

This strenuous six-mile hike can be attempted from either the Davis Creek or the Ophir Creek sides. One trailhead is at Davis Creek Regional Park off Highway 395 in Washoe Valley. The other trailhead is six miles away at the west end of Tahoe Meadows along Highway 431. Taking the trail from Davis Creek can lead you to Rock Lake or past the remains of Upper and Lower Price Lake (destroyed by a landslide) and on to Tahoe Meadows. If you prefer a downhill hike, arrange to leave a vehicle at Davis Creek Regional Park and have someone drop you off at the upper trailhead.

The Ophir Creek Trail includes two small but scenic lakes, a beautiful, 2-mile-long subalpine meadow, tumbling Ophir Creek, and the evidence of a major geological catastrophe. In the spring of 1983, the entire flank of appropriately named Slide Mountain, saturated with meltwater from the thawing winter snows, broke loose and plunged into the canyon of Ophir Creek and partially filled Upper Price Lake with rock debris.