Because no cap rock protects them, the Painted Hills have eroded into low-slung, colorfully banded hills that were originally formed about 30 million years ago. A series of eruptions drifted into beds hundreds of feet deep, layering the brick-red, yellow, black, beige and ocher-hued ash that you now see. It's a fabulous, uncommon sight, best viewed just before sunset. The Painted Hills Unit is 9 miles north of Mitchell, off Hwy 26.
A good viewpoint is reachable by car, but you can also take easy trails to greater heights for even better views. Interpretive walks include the easy half-mile (round-trip) Leaf Hill Trail, which winds over the top of a banded hill, and the 1.5-mile (round-trip) Carroll Rim Trail, which goes to the top of a high bluff for great views.