National Park Mystery Photo 49 Revealed: Wind Plus Sand Plus Time Equals Erosion

Windsculpted sandstone on Santa Rosa Island in Channel Islands National Park. Barbara Polk photo.

Mystery photo 49 was taken on Santa Rosa Island in California's Channel Islands National Park. It shows a sandstone rock face that has been eroded by wind-driven sand.

Situated less than 30 miles off the California coast in the Santa Barbara vicinity, 53,000-acre Santa Rosa is the second-largest of the five Channel Islands. This nearly uninhabited island is renowned for its remarkable biological diversity, but also has interesting terrain features. Some of the most photogenic are rock faces eroded by wind-driven particles. Persistent strong winds, a ready supply of sand, and time measured in centuries produced the many wind-sculpted terrain features that visitors see today on Santa Rosa Island. The example shown here dramatically exhibits the differential erosion of stratified sedimentary rock that has softer rock layered with more erosion-resistant rock. Wind sculpting can produce bizarre shapes, giving rise to the name "howling sand creatures."

Congratulations to the Traveler readers who ID-ed the photo: viewmtn, KevinM, Ken, ron elpelding, Liffey, Eric, tomp2, and David Crowl. All are eligible for our monthly prize drawing.