Hoover Ridge Geology Field Trip and Hike

July 10, 2004

• Location -- This is a geology field trip and hike to look at features in the Little Belt Mountains, located about 60 miles southeast of Great Falls, Montana, U.S.A. Take U.S. Highway 89 to Monarch (in the southeastern corner of Cascade County). A high-quality gravel road goes east for about 12 miles from Monarch along the Dry Fork of Belt Creek to the old mining district of Barker/Hughville. Hoover Ridge is the prominent topographic feature south of the Barker townsite.



• The Hike -- The hike goes along the crest of Hoover Ridge from the Henn Gulch/Ruby Creek Divide to the Charcoal Divide--a distance of about 7 miles. Hoover Ridge is the ridge on the far skyline in the photo above (taken from the Blankenship Divide Road). The trail follows the skyline. It starts and ends at an elevation of 6400 feet above sea level, but climbs to 7400 feet. There are several knobs along the ridge crest. Hiking time is approximately 6 hours for slower hikers, less time for faster hikers.



• The Pioneer Ridge Uplift -- The purpose of this field trip is to look at the Pioneer Ridge Uplift--a block of basement rock 8 miles long and 6 miles wide that was uplifted about 1 1/2 miles vertically about 60 million years ago. The block extends from Dry Fork near Barker almost to Jefferson Creek, south of Neihart. The hike crosses the uplifted block and we will look at upturned beds of Flathead sandstone on both sides of the block.



• Basement rock in the Pioneer Ridge Uplift -- The rocks in the uplifted block are old. Some are 2.7 billion years old--more than half the age of the earth. All were very strongly metamorphosed at about 1.8 billion years ago when they were buried 15 miles or more. Uplift and erosion brought these rocks to the surface where hikers can see them.



• Scenic Views -- Hikers will be able to see many prominent peaks formed by igneous intrusions--laccoliths. Thunder Mountain and Tillinghast Mountain are laccoliths to the west of Belt Creek. The intrusions have the shape of a sand dollar with a flat bottom and a gently arched top. The Barker laccolith, the Clendennin/Peterson Mountain laccolith and the Mixes Baldy/Anderson Peak laccolith are near Hughesville/Barker. The highest peak in the Little Belt Mountains is in the Big Baldy laccolith. Long Mountain and Neihart Baldy are prominent peaks because they are capped by the very resistant Neihart quartzite.



• Field Trip Leaders -- Dr. David Baker, Earth Scientist in Monarch, will conduct the field trip. Co-leader is Vernon Cromwell, Forest Service geologist.



• Registration and Cost -- There is no charge for the field trip; however, prior registration is required. The group size is limited. To register fill out our on-line registration form.. You will be notified of the meeting place and time and other details of the hike.

Geology Field Trips and Hikes  Central Montana Geology  Monarch Area  Contact Us