1970 Map of Twin Sisters

About this map

Twin Sisters stands as a prominent landmark at the intersection of several high mountain ridges within the southwestern Idaho backcountry. This 1970 field-checked survey documents a landscape defined by the transition between the Payette National Forest and the Boise National Forest. The topography is dominated by deep drainage systems, including the headwaters of the Weiser River and the Little Weiser River in the north, and the Third Fork Squaw Creek to the south. The transportation network of the era is almost exclusively composed of a Pack Trail and Jeep Trail system, highlighting the area's role as a remote timber and grazing resource. Notable geographic points like Mill Creek Summit and Woodard Ridge provided critical navigational markers for forest rangers and travelers crossing the tri-county boundary of Adams, Gem, and Washington counties.