City of Rocks National Reserve

The City of Rocks National Reserve is a very unique place. Some of the fantastic granite monoliths and pinnacles here are among the oldest rocks on the surface of Planet Earth. While most climbing rocks are between 100 and 300 feet high, some are in excess of 600 feet high.

Over the years, City of Rocks has become known as a world-class rock climbing area with more than 700 mapped climbing routes available. The City of Rocks National Reserve, as a 14,407-acre property (mind you, about 1/4 of it is privately owned), was first designated by Congress in 1988 and is cooperatively managed by the Idaho Department of Parks and Recreation and the National Park Service. The area was given the name "City of Rocks" by travelers on the California Trail in the early 1840's. This cluster of upthrust granite rocks was a landmark on the northern edge of the Great Basin Desert for emigrants on the California Trail (1843), Applegate (Oregon) Trail (1846) and the Salt Lake Alternate Trail (1848). Some of these emigrants were among the first graffiti artists in America, writing their names on the rock faces with axle grease (that still shows today).

Located as it is in southern Idaho against the northern edge of the Great Basin in the Albion Mountain Range, the climate is reasonably pleasant from April through October, although summer days can see lows in the 30's and high's near 100°. Because of the elevation, you're also going to want some good sunscreen.

The City of Rocks is open year round but some roads are impassable once the snow starts to add up (generally from November through April). The Visitor Center is open from mid-April to mid-October from 8 am to 4:30 pm, seven days a week. From mid-October to mid-April, the Visitor Center is open weekdays (except Federal holidays) from 8 am to 4:30 pm. The only fees charged are for the primitive camping at 64 sites in and among the rock formations: one vehicle, one site for $12 plus tax per night. $5 plus tax for a second vehicle. Limit: two vehicles, eight people, two tents per site. Vault toilets and water taps are centrally located. Most sites have a picnic table, fire grill and tent pad.

Adjacent to City of Rocks National Reserve and State Park is Idaho's newest state park: Castle Rocks. Castle Rocks State Park is a former ranch that contains 1,440 acres with more outstanding rock formations in the setting of an early 20th century homestead ranch. Smoky Mountain Campground at Castle Rocks offers 38 RV-capable campsites with electrical and water hookups.

Recreational activities at the City of Rocks include hiking, backpacking, rock climbing, picnicking, horseback riding, Nordic skiing, wildlife viewing, photography, and primitive camping in designated areas. The road through Almo is open year round but portions of the City of Rocks Back Country Byway may be impassable in winter.

There are more than 22 miles of hiking trails on the property with most trails leading to arches, windows and overlooks. Trail ratings vary from easy to very challenging. Trail lengths vary from short walks to all-day hikes into the heart of the back country. There are trail maps available at the Visitor Center.

The granite in the park can be of radically different ages. An example is the Twin Sisters formation. In the photo below, the Sister on the left is 2.5 billion years old and part of the Green River Complex. The Sister on the right was formed about 25 million years ago and is part of the Almo Pluton. The Almo Pluton was hot magma that forced its way up through the much older Green River Complex and then solidified. At the time this was happening, both layers were still far underground. Over time, the overlying rock has eroded away and the formations beneath have risen and cracked. Erosion then works faster in the cracks and fissures, creating what we see today.

Another element of erosion is "frost wedging:" water seeps into cracks and fissures and expands when it freezes. This action can cause large rock slabs to break off the original formation. This process has already removed some of the layers of rock scarred by those graffiti artists only 160 years ago.

So then, all this erosive "sculpting" has created pinnacles and spires reaching sometimes more than 600 feet above the ground surface. More than 700 climbing routes have been developed at the City of Rocks, most of these on rocks between 100 and 300 feet high. The visitor center offers quite a few privately published climbing guides for sale. While you're in there, you can also get up-to-date information on conditions and area restrictions.

To get there: most folks exit Interstate 84 at exit 216 (Declo) and go south on Idaho Highway 77 to Connor Creek. From Connor Creek they continue southwest on the Elba-Almo Road to the Visitor Center in Almo. The Park Entrance is just west of town.

Folks coming up from Utah usually exit Interstate 84 at exit 245 (Sublette) and go west to meet Idaho 77 at Malta. In the summer the property can also be accessed from Burley via Idaho Highway 27 to Oakley, then over the City of Rocks Back Country Byway.