Of all the buttes in Central Oregon, only a few are hydrovolcanoes, where rising magma intermixed explosively with surface water (such as a lake or underground aquifer) to form a layered ring of solidified volcanic rock known as tuff. One of the more accessible but less-visited of these picturesque tuff rings is Moffitt Butte, just a 50-minute drive south from Bend, off of Hwy 31. Here a 2.6-mile (roundtrip) closed road hike leads up into the tuff ring with long sweeping views, plus cross-county treks to dramatic tuff formations around the rim.

Located on the northern edge of the Fort Rock Basin 60 miles south of Bend, the Devils Garden Lava Field is a 45 square mile maze of lava tubes, spatter cones, tumuli and kipukas. These broad flows of pahoehoe lava are not barren like many in Central Oregon, but feature ponderosa, juniper and mountain mahogany. This flora supports a rich variety of wildlife, including mule deer, bighorn sheep and fabled “lava bears.” Best of all, it's easily explored on a 2.1-mile jeep road hike through the lava field to pine-covered Little Garden kipuka.

What are tumuli (besides the plural of tumulus)? From the Latin tumidus, meaning swollen or bulging in shape, a tumulus is a circular, domed lava structure up to 30’ high and 60’ in diameter, formed by the upward pressure of actively-flowing lava against its cooling crust. Along with its elongated cousin, the pressure ridge, these fascinating lava formations can be explored on a less-traveled trail in the Badlands Wilderness, just 15 miles east of Bend.

In the late 1800s, Central Oregon was not an easy place to reach from the Willamette Valley. Though there was great demand for access by stockmen, who desired to drive their cattle east into the vast bunchgrass plains, the Cascade Range was impassable in winter and the few established trails were difficult and dangerous. That is, until John Templeton Craig pioneered a wagon road across the lava fields at McKenzie Pass — a route that can still be enjoyed today by adventurous hikers.

One of the more interesting geologic features of Central Oregon are kipukas (meaning “a variation or change in form” in the Hawaiian language). These are islands where lava has surrounded patches of older terrain, isolating them from the surrounding landscape. It’s hard to imagine a more dramatic contrast between the dry, rocky, barren fields of lava surrounding the relatively moist, shady islands of forest.