Elkhorn Mountains

The rocks of the Elkhorns were formed about 74 to 81 million years ago (Late Cretaceous time) as a result of the Farallon tectonic plate subducting beneath western North America and allowing magma to rise to the surface. The Elkhorn Mountains Volcanics are extrusive rocks related to the plutonic granites of the Boulder Batholith. Fossilized dinosaurs killed by ash from the Elkhorn volcanoes have been found at Egg Mountain near Choteau, Montana. Volcanic flows, lahars, and ash falls from sources are thickest within a radius of about from the Elkhorns. The volcanics probably originally covered an area of about in diameter. Mineral deposits associated with the Elkhorn Mountains Volcanics include silver mined at Elkhorn, Montana, copper mined at Butte, and gold at the Golden Sunlight Mine near Whitehall, which is associated with a breccia pipe in the volcanics. The mountain range seen today is related to regional structural uplift dating mostly to Oligocene time. ==History==

Evidence of human settlement in the area dates back to over 12,000 years before present. The area was included in the 1804 Louisiana Purchase. The area was designated as common hunting ground per the Treaty with the Blackfeet of 1855. In the 1860s, discovery of gold brought many prospectors into the area. A silver boom followed in the 1869. Silver miners named the Elkhorn Mountains because of the large number of elk (wapati) found there. At its peak, the town of Elkhorn, now a ghost town, had 2500 inhabitants. ==The Land==

. A forest fire in 1988 burned 47,000 acres (190 km2) of the mountain range, leaving carpets of seedlings growing into new lodgepole pine forests. The land has been used extensively in the past for gold and silver mining, logging, and open range grazing, leaving a noticeable impact; most notably the abandoned mining town of Elkhorn. Recently with efforts conducted by the BLM, Montana FWP and Helena National Forest, new conservation and wildlife management plans have been put into place including big horn sheep reintroduction and the westslope cutthroat trout restoration program. Management of the 2000+ elk herd in the area and the suppression of noxious weeds is also an ongoing task. Despite the impacts of mining, around 100,000 acres of the Elkhorns were still roadless in 1992; this included 85,000 acres of roadless National Forest land as well as adjacent BLM, state and private lands. Congress designated 175,000 acres of the range as the "Elkhorns Wildlife Management Area," and one of Montana's most productive elk herds inhabits the range. Because the Elkhorns are higher in elevation than the nearby section of the Continental Divide, they catch more moisture than do most other ranges east of the Divide. For this reason, the Elkhorns are especially diverse, with 148 documented vertebrate species. ==Climate==

Tizer Basin is a SNOTEL weather station situated by Big Tizer Creek near Bullock Hill. , Tizer Basin has a subalpine climate (Köppen Dfc). ==See also==