There are several mountain bike trails in the area, but this is an out-and-back gravel ride of about 40 miles and 2,500 feet of climbing, over somewhat rolling terrain, gradually uphill on the way out. I would find it rather tedious to do by myself but it makes a great group ride.
Drive up on Hwy 77 north from Tucson towards Oracle. About 4.8 miles after Hwys 77 and 79 split you will see Willow Springs Road signed on the left. Turn left and park in the large dirt parking area on the left.