Junction of Highway #138 West. Julesburg city limits - Elevation 3477 ft. Highway #138 overlaps #385 at this point - Highway # 138 is called The South Platte River Trail Scenic Byway. The South Platte River Trail take travelers on a historical and scenic tour of the northeast corner of Colorado. The 19-mile trail loop traverses the Overland/California and ranges the state's Pony Express trails, as well as the routes of the first Transcontinental Railroad, telegraph, and automobile road. City of Burlington to Colorado/Nebraska State Line