You’re probably wondering about the name.  William Granstaff , a black man, settles in Moab in 1877 and successfully becomes a cattle rancher. The trail leads you through this glorious canyon composed of Navajo Sandstone, Cottonwoods, Willows, Juniper, Pinyon Pine, some prickly Cactus and one refreshing perennial creek.  The big payoff is at the end(2 1/4 miles from the trailhead), the Morning Glory Natural Bridge, at 243 feet wide.  A natural bridge is an arch but with water running under it.