The St Regis River begins at Lookout Pass in which mountain pass on the Idaho/Montana border?
Lookout Pass Lookout Pass is a mountain pass in the Rocky Mountains of the northwestern United States. In the Coeur d'Alene Mountains of the Bitterroot Range, the pass is on the border between Idaho and Montana, traversed by Interstate 90 (formerly U.S. Route 10) at an elevation of 4710 ft above sea level.
Santiam Pass Santiam Pass is a 4817 ft mountain pass in the Cascade Range in central Oregon in the United States. It is located on the border between Linn and Jefferson counties, about 18 mi northwest of Sisters, between the prominent volcanic horns of Three Fingered Jack to the north and Mount Washington to the south. Several other smaller volcanoes, including cinder cones and tuyas, are found near the summit of the pass. U.S. Route 20 connects eastern Oregon with the valley of the Santiam River on the west via Santiam Pass. One of the 19 or 20 lakes by the name of Lost Lake is located beside the highway just west of Santiam Pass. The pass may be approached from the west by three distinct routes: