Photo #23436 - Roadside turnout with historic information sign The Jim Bridger Trail 1864 - North of this point is the Jim Bridger Trail. The Devils Backbone, the roughest decent on the trail, situated at the northern edge of the plains the trail drops down into the Whistle Creek Valley. In the spring of 1864 Jim Bridger guided 62 wagons from Fort Casper northwest through the Big Horn Basin to Virginia City Montana. Yellowstone National Park eastern boundary to Cities of Cody - Greybull - Worland Wide open grasslands and spectacular scenery. From Grand Teton to Yellowstone National Park, from the Shoshone National Forest to the Eastern Great Plains, Wyoming is beautiful and awesome. Natural wonders that have inspired everyone.