Whitmore Canyon Overlook, Frog Spring, and Whitmore Point. Most high clearance 4x4s can make the drive from the Mt. Trumbull Schoolhouse to Whitmore Canyon Overlook deep in the Grand Canyon. Bedrock steps on the way to Whitmore Point make this road impassible to some stock pickups and SUVs. The road to Frog Springs is only for Jeeps and UTVs. Tires need to be rugged and in good condition to handle miles of sharp lava or limestone rocks on these roads.