This unique geologic area became a landmark in 1843 for California bound emigrants. A few granite pinnacles and monoliths are in excess of sixty stories tall and 2.5 billion years old. The smooth granite faces offer exceptional rock climbing. The Reserve is managed by the Idaho Department of Parks and Recreation under a cooperative agreement with the National Park Service.
Flora and Fauna
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.
City of Rocks is one of the finest granite face climbing sites anywhere, with about 700 routes developed to date. One hundred 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 routes are market and rated for abilities. Most of the routes have chains or are bolted and there are several excellent guide books to help you find the routes that will suit your tastes and abilities.
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. However, 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.
California bound wagon trains (1843-1882) left Raft River Valley and travelled 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.
City of Rocks is located in south-central Idaho within the northern edge of the Basin and Range geologic province. Outdoor recreation can be pleasant from April through October. Summers are generally dry with 10 to 15 inches of precipitation in winter and spring. Summer temperatures range widely with night time lows occasionally approaching freezing and midday highs nearing 100° F. Thunderstorms may occur in July and August.
City of Rocks National Reserve Visitor Center and Headquarters
Phone: (208) 824-5901
By David Fowers for getoutexplore.com
Photo by wilson44691 – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=61374456