Southern Idaho’s best-kept secret is a 2.5-billion-year-old granite city rising 60 stories from the desert

It’s two miles from Utah’s border

Southern Idaho keeps this one quiet. City of Rocks National Reserve covers 14,407 acres at the bottom of the Albion Mountains, and the granite spires here climb as high as 60 stories above the sagebrush.

The reserve sits near the tiny town of Almo, just two miles north of Utah.

It’s part of the National Park System, but the Idaho Department of Parks and Recreation runs the day-to-day operations on the ground.

The formations look so much like a skyline that 1800s travelers named it themselves, and the name stuck.

Some of this granite is 2.5 billion years old

The oldest rock here belongs to the Green Creek Complex, and at 2.5 billion years old, it ranks among the oldest exposed granite in the western United States.

Most of the tall spires you see today come from a younger formation called the Almo Pluton, about 28 million years old.

Starting in 1843, emigrants on the California Trail crossed Granite Pass right through this landscape. They smeared their names in axle grease on the rock faces, and you can still read those messages at Register Rock.

The Shoshone and Bannock tribes lived in this area long before those wagon trains arrived, hunting game and gathering pinyon pine nuts.

700 climbing routes on granite walls

More than 700 established routes make City of Rocks one of the top granite climbing spots in the country. You can find everything from beginner-friendly 5.0 grades to expert-level 5.13 and harder.

Crack climbing, face climbing, slab climbing, it’s all here on the Almo Pluton granite. Back in the 1980s, some of the hardest climbing routes in the nation ran through this reserve.

If you’ve never climbed before, the reserve runs a Climbing Experience Program where guides bring all the gear and walk you through the basics.

A 300-foot walk to a natural stone arch

Twenty-two miles of hiking trails cut through the reserve, and they range from quick walks to full-day backcountry treks. The Window Arch Trail gets you to a natural stone arch in about 300 feet.

Bath Rock Trail loops past a formation with a natural bowl on top that fills with rainwater. Creekside Towers Trail runs 0.6 miles along dramatic rock walls.

If you want something longer, the North Fork Circle Creek Trail stretches more than six miles into the backcountry.

Zero artificial light inside the reserve

City of Rocks earned International Dark Sky Park certification in January 2023, and the reason is simple: there is zero artificial lighting within the reserve’s boundaries.

The reserve worked with nearby Castle Rocks State Park to swap all outdoor lights for dark-sky-friendly fixtures.

On a clear night, you can see the Milky Way the same way the Shoshone people and California Trail emigrants once did.

The reserve hosts star parties, constellation tours, telescope viewing events, and a dark sky junior ranger program for kids.

179 bird species call this desert home

Golden eagles, canyon wrens, pinyon jays, and Idaho’s state bird, the mountain bluebird, all live in and around the reserve. Altogether, 179 documented bird species use this landscape.

The pinyon-juniper woodlands support birds you won’t easily find elsewhere in Idaho, including the juniper titmouse and Virginia’s warbler. Ferruginous hawks and burrowing owls patrol the open ground.

Stop by the visitor center before you head out, because they keep a board of recent sightings so you know what to look for.

Idaho’s only pinyon pine forest grows here

You won’t find another pinyon pine forest anywhere else in Idaho.

The single-leaf pinyon pine that grows here is the world’s only single-needled pine species, and these trees sit at the northernmost edge of their natural range in the Albion Mountains.

The Shoshone people relied on pinyon pine nuts as a food source for thousands of years.

Beyond the pines, the reserve holds sagebrush-steppe, aspen woodland, and riparian habitat, packing a wide mix of plant life into a small area.

Read 1850s axle grease signatures on the rock

Elephant Rock, Morning Glory Spire, Bath Rock, and Bread Loaves are a few of the named formations worth tracking down. Register Rock still holds the axle grease signatures California Trail emigrants left in the 1850s.

Drive up to the Circle Creek Overlook at 6,120 feet, and on a clear day you can see more than 100 miles to the Bear River Mountains.

A Geological Interpretive Trail near the overlook explains how exfoliation shaped these formations. Most of the big rocks sit just a short walk from the gravel roads.

64 campsites tucked between granite boulders

The reserve has 64 standard campsites and three group sites spread among granite boulders under juniper, pine and aspen. Every site comes with a fire ring, a picnic table and access to vault toilets.

Drinking water runs at Bath Rock and Emery Pass Picnic Area during warmer months. Here’s the part that surprises people: there is no entry fee.

The reserve stays open year round, but water and some facilities shut down in winter, so plan your timing if you want the full setup.

Castle Rocks State Park sits a few miles north

Castle Rocks State Park borders the reserve to the north and carries the same type of granite formations.

You get additional hiking trails, rock climbing, a stocked fishing pond and a 3-D archery course with more than 20 stations. The park has its own campsites and a glamping yurt if you want a roof over your head.

Among the rock formations, you can find pictographs made by Indigenous peoples, some dating back centuries. Castle Rocks charges $7 per vehicle per day, while the national reserve next door is free.

A 50-mile byway loops the Albion Mountains

The City of Rocks Backcountry Byway runs 50 miles around the Albion Mountains and passes right through the reserve.

It connects the historic town of Oakley with Almo, and gravel roads through the reserve let you drive slowly past many of the big formations.

Mountain biking and horseback riding are allowed on designated trails, so you don’t have to explore on foot. In winter, the trails open up for snowshoes and cross-country skis in both the reserve and Castle Rocks.

Almo has maps, a video and one road out

Almo is an unincorporated ranching community that serves as base camp for the reserve.

The shared visitor center for both City of Rocks and Castle Rocks sits right in town, and inside you’ll find maps, an introductory video on the area’s geology and history, and a junior ranger program for kids.

This cattle ranching community dates back to the 1870s and still runs on that economy. The nearest larger town is Burley, about 45 miles north along Highway 77.

Explore City of Rocks National Reserve in Idaho

You can reach City of Rocks from Burley, about 45 miles to the north, or plan for a roughly 180-mile drive from either Boise or Salt Lake City.

Come through Almo, because winter access via Oakley is not recommended due to road closures. All roads inside the reserve are gravel but handle standard vehicles.

The visitor center is open Wednesday through Sunday, 8 a.m. to 4:30 p.m., with seasonal changes. There is no cell service inside the reserve, so download your maps before you arrive.

This article was created with AI assistance and human editing.

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