Photo #6034 - Junction Utah Highways US 191 and SR 279 Potash Road Eastern end of Utah Highway SR 279 Potash Road - Lower Colorado River Scenic Byway at mile marker 129.9 on US 191 and 4.1 miles north of downtown Moab, Utah or 27.3 miles south of Exit 180 on I-70. The road immediately crosses Moab Canyon Wash and then continues southwesterly along the base of the cliffs of Moab Valley, Utah toward The Portal, where the Colorado River leaves the valley. - For highway travel north or south via U.S. Highway #191 - See Milebymile.com U.S. Highway #191 - Utah Road Map Travel Guide Arizona/Utah State Line to Crescent Junction for driving directions. Potash - Lower Colorado River Scenic Byway