Geology

The landscape of City of Rocks has been sculpted from granite that was intruded into the crust during two widely spaced times. The granite that composes most of the spires is part of the 28 million year old Almo pluton. Some of the spires are made of granite that is part of the 2.5 billion year old Green Creek Complex, and contains some of the oldest rocks in the western United States. Learn more about the geology of the reserve by hiking the new Geological Interpretive Trail.

Rock Climbing

City of Rocks is one of the finest granite face climbing sites anywhere, with about 700 routes developed to date. 100 to 300 foot spires provide most of the climbing opportunities, although the park does offer 600 foot spires which provide extended adventures. The winter months provide excellent conditions for ice climbing.

The climbing experience program offers visitors an introduction to the experience of climbing in a supervised setting.

Cultural History

California bound wagon trains (1843-1882) left Raft River Valley and traveled through this area and over Granite Pass. Names and initials of emigrants written in axle grease are still visible. Emigrants consistently referred to the city as one of the memorable scenic wonders of a phenomenal journey: "This is one of the greatest curiosities on the road." wrote Eliza Ann McAuley in 1852.

Historic Van Tour

Natural Resources

The Reserve boasts Idaho's champion pinyon pines, at more than 55 feet. City of Rocks pinyon pine forest is the northern most extension into Idaho. Wildflowers are abundant in the spring and summer months. The diverse habitat of the reserve supports a large variety of mammals, birds, reptiles, and invertebrates.