North of Moab, the Monitor and Merrimac Trail is a 14 mile figure-8 loop. The deep sand and slickrock challenges of the Monitor and Merrimac Trail make the route a local favorite. The neighboring buttes of Entrada sandstone are named for the Civil War ironclads, which they superficially resemble. Soaring chocolate cliffs, natural arches stuck like giant handholds high on the sandstone walls, and expanses of smooth rock create top-notch scenery. You can circumnavigate the Monitor on a level bench of stone, then follow the swirling lines of Navajo sandstone while gliding around the Merrimac.
The trip has several variations all coming in around 14 miles. Selecting an alternative depends on how much deep sand you are willing to slog through.
To reach the mountain biking trailhead from Moab, head north on US191 for 14.6 miles to Mill Valley Road. Turn left heading west on Mill Valley Road for 0.6 miles to the signed trailhead parking area.
From the trailhead, the easiest route -- that is the one with the least amount of sand -- follows the signs for Mill Canyon and its Dinosaur Trail. Once in the canyon, mountain bike ride the road, climbing gradually.
On top of Courthouse Pasture, the sand traps begin as the road takes you to the east end of the Merrimac, the larger of the two buttes. Once there you can follow your fancy around the buttes and eventually pick up the return trail on the west end of the Merrimac. This road will take you back into Mill Canyon.
Overall, Monitor and Merrimac Trail is the 18th most popular mountain bike trail of all 73 mountain biking rides in Utah.