Carbonate Mountain is the steep, sage-covered hill that rises about 1,400 feet directly west of downtown Hailey. The summit sits at 6,714 feet, and the Big Wood River runs along its eastern base. Because the trailhead is a short walk or ride from Main Street, it is one of the busiest trails in town, and locals treat it as a quick workout before or after work. Much of the mountain is private land, but the trail corridor crosses parcels managed by the Bureau of Land Management through its Shoshone Field Office.

The trailhead is on the west side of the river at the end of Bullion Street, next to Hop Porter Park and Lions Park. The lot is small and fits roughly ten cars, so walking or riding from town is often easier. Restrooms are in the park across the bridge. A short distance above the parking area the route passes a set of concrete water tanks, and soon after that the trail forks. The right branch goes more or less straight up the ridge. The left branch climbs a long series of switchbacks across the face. The two routes cross each other several times, so it is easy to mix them on the way up and down.

The standard hiking loop is about 3.7 miles with roughly 1,300 feet of climbing, and most people finish it in about an hour. The direct line gains around 1,300 feet in less than a mile, with grades above 30 percent in places. The switchback route to the top is closer to 2.4 miles one way and is the better choice for anyone who wants a steady pace. Trail runners use both, and some make it a regular sunrise run. The south ridgeline is an easy scramble with no technical sections, but the footing is loose gravel in spots and the east face below it is crumbly rock that is best avoided.

From the ridge you look straight down on Hailey, north up the valley toward Bald Mountain and Sun Valley, and south toward Bellevue. On clear days the Pioneer and Boulder mountains show up on the skyline. The vegetation is mostly sagebrush and grass. Parts of the ridge burned in the 2013 Beaver Creek Fire, and the slopes are still open and dry.

Mountain bikers ride a longer loop of about six miles that is rated advanced. It climbs the switchbacks for most of the way up, then follows a steep, loose and rocky ridge. From the top the route heads north past a large set of power lines and drops on singletrack to Croy Creek Road, which leads back east to the trailhead. Riders describe it as a grunt of a climb with a lot of foot traffic, so expect to yield to hikers, runners and dogs.

The south-facing slope loses its snow early, and Carbonate is usually one of the first trails in the valley to open each spring. Spring and fall are the best seasons. In summer there is almost no shade and the sun is intense by mid-morning, so start early and carry more water than you think you need. The trail is popular with dog owners. Some people snowshoe it in winter. No permit is required, and visitors are asked to pack out everything they bring.