The 1887 Sonora earthquake dislodged massive boulders lining the canyon walls , which came to rest in the valley below . In 1905 the newly created U.S. Forest Service began administering Sabino Canyon . During the Great Depression , the Works Progress Administration ( WPA ) and Emergency Relief Administration ( ERA ) built Sabino Dam and nine bridges over Sabino Creek in an attempt to build a road to the top of Mount Lemmon . The road travels about 4.5 miles into the canyon , but was not completed due to the steep terrain at the end of the canyon
1887 Sonora earthquake
1887 Sonora earthquake
Sabino Canyon