Geology of Tenderfoot Creek Experimental Forest Little Belt Mountains, Meagher County, Montana

Geographic Setting The Tenderfoot Creek Experimental Forest in the west-central part of the Little Belt Mountains occupies a transition zone in the west-central part of the Mountains-a transition from rolling mountain parks with rounded peaks that rise about 500 feet above the upland of the range to deeply incised canyons that drain the west end of the Mountains. The Experimental Forest is bisected by Tenderfoot Creek, which is incised as deeply as 2400 feet into the upland. The steep inner canyon of Tenderfoot Creek opens upward onto narrow parks, which are rimmed on the north and south by, rounded peaks that rise to elevations of about 7200 to 7600 feet. At the east end of the experimental forest, the divide of Onion Park separates drainage flowing east into Belt Creek from drainage flowing west into Tenderfoot Creek and the Smith River. Quartzite Ridge, Williams Mountain and Woods Mountain on the south, and the ridge of Iron Mountain north of Tenderfoot Creek enclose the Tenderfoot Creek drainage. Thus the Experimental Forest covers the upper end of a west-sloping basin that drains steeply into the Smith River, about 12 miles to the west. This geographic setting is controlled by the resistance to erosion of rock units that underlie the area and by young geologic uplift of the mountains. These controls are described in the following account of the geology of the experimental forest.