The canyon became a main transport corridor in the region during the 1880s. Settlers established a number of ranches in Ninemile Canyon, and even a short-lived town named Harper. No longer heavily traveled, the rugged canyon road was used mostly for recreation and tourism through the end of the 20th century. The discovery of rich deposits of natural gas deep beneath the West Tavaputs Plateau has brought an influx of industrial truck traffic since 2002. The large amounts of fugitive dust produced by the trucks' passage may be damaging the rock art. Public debate is ongoing about how best to balance energy development in the canyon against the preservation of its cultural resources.