Potash Plant The Potash Scenic Byway SR 279 ends here at the Potash Plant. Various salts are mined from deep beneath the crust of the earth, then concentrated by evaporation in ponds that the Potash Trail (see below) circumnavigates several miles beyond the end of this road. The concentrated brine and salt slurry is then transported to the refining mill (Potash Plant) where the potash mineral (used primarily as a chemical fertilizer) is separated from the sodium chloride (table salt). The Potash Trail that continues downriver beyond this point is paved for another 1.5 miles to the Potash Boat Ramp. The Potash Trail joins the White Rim Trail and the Shafer Trail in Canyonlands National Park. The steep Shafer Trail switchbacks, bringing you to the Island in the Sky District and the Dead Horse Mesa Scenic Byway SR 313 (see separate road map log), are 12 miles ahead. End of Road Map Travel Guide. -e Potash - Lower Colorado River Scenic Byway