Proceeding west to east for 122 miles (nearly 200 km), Utah Highway 12 starts south of Panguitch at an intersection with US-89, crosses part of Dixie National Forest and Bryce Canyon National Park, continues through the small towns of Tropic, Cannonville, and Henrieville. It crosses various parts of Grand Staircase-Escalante National Monument (GS-ENM), continues northeast through Escalante and over the Escalante River, then north through more of GS-ENM, Boulder, the Aquarius Plateau, Grover, ending in Torrey at an intersection with SR-24, five miles (8 km) west of Capitol Reef National Park. The 30-mile (48 km) long portion of the highway that ascends and descends Boulder Mountain on the Aquarius Plateau is known as Boulder Mountain Highway.