Intermountain Region

Head south on I-15 from Salt Lake City, UT. Take the Scipio exit (188) to US Highway 50. Travel 30 miles on Highway 50 to Salina. Travel from Salina to Sigurd on I-70 (take exit 48, which is the start of Utah Highway 24). Follow Highway 24 south to the Fish Lake turnoff (Utah Highway 25, the Fish Lake Scenic Byway).

Travel north on I-15 from Southern Utah or Cedar City, UT. Take exit 95, travel southeast on Utah Highway 20 for 21 miles. Then take US 89 north to Kingston. At Kingston, take US Highway 62 east and then north at Otter Creek Reservoir to its junction with Utah Highway 24. Head south on Highway 24 to the Fish Lake turnoff (Utah Highway 25, the Fish Lake Scenic Byway). Follow Utah Highway 25 northeast 13 miles to the end of the byway. Here you will enter the Fishlake National Forest about three miles along the route.

Much of the underlying rock of Fish Lake Basin is composed of basalts that flowed from fissures then cooled. The basin itself formed when one block dropped down between two faults on either side. On the southeast side of the lake lie the slopes of Mytoge Mountain and on the northwest side, Fish Lake Hightop Mountain.

The fault blocking occurred at different times and at different places along a10 mile stretch. The ends of the basin have not settled concurrently as recent evidence suggests that the lake once drained to the south rather than its current route to the north at Lake Creek.

Glacial activity also played a role in carving canyons and depositing moraines in Fish Lake Basin. Well-noted evidence of this activity is at Pelican Canyon (Godfrey.)

From Salt Lake City, UT, head south on I-15. Take the Scipio exit (188) to US Highway 50. Travel 30 miles on Highway 50 to Salina and follow the signs to merge onto I-70. I-70 passes through Salina Canyon.

A quick drive through Salina Canyon on I-70 takes the visitor on a whirlwind geologic tour. Classified as a high-altitude desert, the area of Salina Canyon was once a hot, humid coastal plain between the mountains and the sea. About 65 million years ago, near the end of the Cretaceous period when dinosaurs still thrived, water inundated the dense vegetation so quickly that decomposition could not take place resulting in the thick coal seams found today. Sea level fluctuated burying the coal bed beneath other sedimentary layers. These coal seams are very apparent, even from the road.

Since then, the Colorado Plateau experienced uplift, raising the region over a mile. Movement of the North American plate and uplift of the plateau have helped to dramatically change the climate found in Salina Canyon today (Godfrey).

This is located in the eastern most portion of the Fishlake National Forest. Head south on I-15 from Salt Lake City, UT. Take the Scipio exit (188) to US Highway 50. Travel 30 miles on Highway 50 to Salina. Travel from Salina to Sigurd on I-70 (take exit 48, which is the start of Utah Highway 24). Follow Highway 24 south towards the town of Loa (At milepost 41, Thousand Lake Mountain is directly ahead). Before reaching Loa turn and head northeast towards Fremont. From Fremont, go 5 miles north on UT-72 and go southeast on Baker Ranch Road, which then curves northeast and joins the Cathedral Valley Scenic Byway. The road turns south again and loops back to UT-72.

A portion of the Great Western Trail crosses Thousand Lake Mountain north and south. Campsites and hiking opportunities abound. On the eastern side of the mountain lies, the very colorful and much less visited portion of Capitol Reef National Monument named Cathedral Valley. Stunning mountainous terrain drops to red valley floors dotted with amazing monoliths and other red rock features.

Thousand Lake Mountain, made up of Miocene volcanic rocks, capped by Pliocene lava flows (Chronic, 1990.), is a misnomer when one considers how few lakes really exist in its boundaries in comparison to the nearby Boulder Mountain.

Volcanic rocks that flowed rather fluidly from vents and fissures to form relatively flat surfaces cap Thousand Lake Mountain. Beneath the volcanics lie the Mesozoic sedimentary formations of the Moenkopi, found on the south side, and the Mancos Shale to the north. However, landslide debris buries most of these colorful formations and gives Thousand Lake Mountain its distinctive shape. This is due, in part, to high relief as well as the sequence of rocks present.

In the much cooler, wetter periods of Utah's history, such as 10,000 years ago, landslides were much more prevalent than today. Water seeping into the fractured volcanic cap rocks was forced to move laterally once it met the impermeable shale. The water would also turn shale into slippery clays creating less friction for the cap layers. This combination effectively caused the cap layers to slide (Godfrey.) 

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).

The Pahvant Range lies just west of Richfield, UT, extending south where I-70 works its way through the divide between the Tushar Mountains and the Pahvant Range, to the north where Scipio lies. The Canyon Mountains to the north of the Pahvant Range are separated by a divide that I-15 traverses.

The east side of the Pahvant Range differs widely from the west in age, composition, formation, and deformation. The west side of the Pahvant Range consists of drab colored, Paleozoic marine deposits including limestones, quartzites, sandstones, and shales. Compressional forces due to continental collision thrust those layers up and over other sedimentary layers creating a high mountain range. On the east, those ancient mountains shed their deposits, forming colorful red and yellow Tertiary age conglomerates, sandstones, and shales at their base.

The west side is well weathered and eroded with steep slopes and tall cliffs as well as the fact that the rocks dip nearly vertical. The east side is rounded and nearly flat lying. Faults are still active in the area causing the range to continue to uplift.

The bulk of the Canyon Mountains are similar to the west side of the Pahvant Range (Godfrey.)

From Highway 89, south of Richfield, UT, just past Big Rock Candy Mountain, to the west begins the Tushar mountains. They continue south and end near Circleville, UT. Highway 89 offers the eastern view of this range.

The Tushar Mountains consist of the Bullion Canyon Volcanics from 22-35 million years ago and the Mount Belknap Volcanics from roughly 21 million years ago. Catastrophic eruptions with large volumes of ash deposited as far north as Richfield formed the Joe Lott Tuff Member and led to the collapse of the Mount Belknap caldera 19 million years ago. 

Fluvial, eolian, and glacial activity has largely eroded these volcanics. Driving through Marysvale Canyon (see Big Rock Candy Mountain below) reveals a profile of the volcano's flank and several flows to the east. Sulphur-laden deposits with their distinctive yellow color are also visible in this region and attest to the later stages of the volcanic activity (Godfrey.)

The Paunsaugunt Fault forms the southeast edge of the Paunsaugunt Plateau. Bryce Canyon's rim is also the dropped side of this fault. Along this fault, Cretaceous rocks border the Claron Formation. The capping Claron Formation, regionally ranging in age from Paleocene to middle Oligocene, can be identified by its pink, cliff forming features. Thought to have formed during the transition period from fluvial environments to deltaic and lacustrine conditions, the oxidized iron in the muds and silts contributed to the pink color indicative of the Pink Member. The White Member, a limestone with interbedded siltstone and few fossils, has eroded away and can only be seen on the highest points of the Paunsaugunt Plateau (Davis et. al 2003.)

Drive 20 minutes south of Richfield, UT on Highway 89.

This landmark mountain and it's "lemonade spring" get their names from the brightly colored clays and rusty colored spring water. The clays were hydrothermally altered forming oxidized iron, limonite, and weakened in the process. Erosion readily took hold of the weakened materials to elaborate the colorful display. Across the canyon, is a small gray igneous intrusion that may have been the cause of the hydrothermal alteration. Melting its way through the layers, the intrusion may have heated and acidified the hot water.

Five miles north of Big Rock Candy Mountain, tertiary volcanic tuff and lava fragments form a mudflow deposit from a Mount Belknap eruption (see Tushar Mountains above). Tilted greenish and pinkish layers of volcanic ash are also visible just north of the I-70 Junction near Sevier (Chronic, 1990.)

Head south on I-15 from Salt Lake City, UT. Take the Scipio exit (188) to US Highway 50. Travel 30 miles on Highway 50 to Salina. Travel from Salina to Sigurd on I-70 (take exit 48, which is the start of Utah Highway 24). Follow Highway 24 south to the Fish Lake turnoff (Utah Highway 25, the Fish Lake Scenic Byway). Pelican Canyon is located at the north end of Fish Lake. A road diverges from Fishlake Scenic Byway to Pelican Overlook.

Pelican Canyon was carved out by glaciers and Pelican Overlook sits atop the moraines left from that activity. Melting glaciers washed sediment out into the lake in a fan-shaped deposit nearly dividing the Fish Lake in two. A narrow straight remains between Widgeon Bay and the main part of Fish Lake at Pelican Point.