Find Me Gallery Scarlet Hedgehog Cactus The red, nectar-filled blooms of this cactus are favored by hummingbirds. Colorado River Started as two separate river systems that began carving the canyon 17 million years ago. By 6 million years ago, they joined as a single stream. Rock Shelter Cougars use ledges just below the canyon rim for daytime rest, but rarely traverse the mile-deep canyon. Deer Bones From an old kill; cougars sometimes drag prey to secluded places to eat alone. Shiva Temple A mile-wide mesa.