Some of the more geologically and visually interesting canyons in Central Oregon are found on the southeast slopes of the Crater Lake caldera. In these lightly-visited canyons are found hundreds of stark stone pinnacles, which have eroded out of the volcanic ash of remnant Mount Mazama. The pinnacles in Wheeler Canyon are easily accessible by car at a viewpoint in Crater Lake National Park, while the rock towers in lower Sand Canyon require a challenging, cross-country bushwhack of 2.7 miles roundtrip.