There are many colorful rock formations spread across Arizona, and some of the more spectacular are located in Canyon deChelly on the Navajo Reservation at Chinle. The most prominent is Spider Rock, a towering sandstone obelisk that rises almost 900 feet above the floor of the canyon. Others aren’t quite as spectacular, but they’re nearly as large and they look like gigantic slates, kids mittens and huge lumps of red clay that were just dumped there by some giant sculptor.