Ninemile Canyon is a canyon, approximately 40 miles long, located in Carbon and Duchesne counties in eastern Utah, United States. Promoted as "the world's longest art gallery", the canyon is known for its extensive rock art, most of it created by the Fremont culture and the Ute people. The rock art, shelters, and granaries left behind by the Fremont make Ninemile Canyon a destination for archaeologists and tourists alike.
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.
Wikipedia https://en.wikipedia.org/wiki/Ninemile_Canyon_(Utah)
Address 9 Mile Rd, 84520, United States
Coordinates 39°48'2.395" N -110°22'0.443" E