Volcanic formations near Camp Verde resemble tepees
Hikers commonly experience a feeling of renewal on trails, especially those with budding vegetation. A trail can look different each trip, depending upon the season, rate of plant growth, animal activity and even time of day.
In contrast, the Cottonwood Basin Tuffs (tuff - rock made from compacted volcanic fragments) in the Coconino National Forest near Camp Verde provide a sense of stepping into prehistoric times.
Locals call the cone-shaped formations Tepee Rocks. Wayne Ranney, who teaches geology at Yavapai College, calls the tuffs "hoodoos," which are "erosional remnants." The word hoodoo, probably coined by cowboys to describe the rocks' spooky appearance, now is an accepted geologic term for a column of rock weathered into a strange shape.
A common misconception says the concrete-like columns arose as chimneys around vents (fumaroles) that let volcanic gases escape. The truth, Ranney said, probably is that a thick sheet of volcanic ash from the Hackberry volcano some six miles away blew across the entire landscape between 9 and 11 million years ago. Ash that set underground became cemented by groundwater, with an extra-hard cap on top. Erosion by the elements caused their present shapes in the tilted landscape. Toward the Verde River to the west, such remnants have eroded completely, while to the east, the tuffs have yet to be exposed to the surface.
Situated in a large draw below a cliff, the tuffs are an anomaly over a few acres in an otherwise typical desert landscape. The 10- to 12-foot tall, and in some places 30-foot thick tuffs resemble oversized termite mounds with a Swiss cheese look from their many round indentations and holes. A hole formed when a large piece of pumice broke off and water sat in the depression, dissolving the cement into an increasingly larger hole.
For a longer hike with fantastic views, grab your water bottle and follow any of the small draws, or keep going on Forest Road 500. The north slopes of distant mountains, including Hackberry, often have snow during winter months.
Directions: Take State Route 260 out of Camp Verde to Fossil Creek Road. Drive 1.1 miles, turn right onto FR 500, park and head left about 0.1 mile uphill on the narrow road that ends at the cliff above the tuffs. You can go up FR 500, but the tuffs are on the opposite side of the hill it skirts. Either way, you'll need to bushwack to reach the rocks.