 Then west along the present Wyo/Colo border to Green River then NW to Fort Bridger.This route sometimes referred to as the "disease free" or "middle" route increased each year in numbers of Emigrants and cattle drives until by 1857 becoming the most heavily traveled or the major trail to California.In 1857 a new cutoff of the Cherokee Trail was established when the US Army built a road over Bridger Pass to Fort Bridger.