Official Forest Service map illustrates the route the emigrants followed through the Sierra Nevadas to the rich lands of California. Much of the route is on paved roads or improved gravel or dirt roads. Donner Pass is a three hour minimum hike on a trail, and another segment is on an unimproved dirt road. Descriptions of each segment are provided. located in Tahoe National Forest map shows the trail from Dog Valley near Truckee River west to Rollins Reservoir.