Quick FactsOverview
About Bronco Billy Hot Spring
Bronco Billy Hot Spring, also known as Deer Creek Hot Spring, Idaho is a roadside geothermal spring on the Banks-Lowman Highway (Highway 17) in Boise County, along the South Fork Payette River in the Boise National Forest. The source water is extremely hot and flows through a metal channel from the hillside into a shallow rock-walled pool with sand, rock, and gravel bottom. Banks, a small community at the junction of the North and South Forks of the Payette River, is the nearest settlement with services. Boise is approximately one hour to the west.
Bronco Billy was a popular soaking destination until a major mudslide on December 31, 1996, buried the spring and dammed the Payette River, covering the highway with water for three weeks. The original culvert pool on the river side of the highway was destroyed and has not recovered. The remaining source pool above the road is extremely hot and shallow. This is one of several natural hot springs in Idaho along the Banks-Lowman corridor, which also includes Skinny Dipper (closed by BLM), Pine Flats, and Kirkham Hot Springs.
The spring shares a pullout with the former Skinny Dipper Hot Springs at mile marker 4 on the Banks-Lowman Road.
Location & Access
Getting to Bronco Billy Hot Spring
Bronco Billy Hot Spring is located at a roadside pullout at mile marker 4 on the Banks-Lowman Road (Highway 17) in the Boise National Forest, with no hiking required. The pullout is a large gravel area on the river side of the road.
From Boise, drive north on Highway 55 to Banks (approximately 45 miles), then turn east onto the Banks-Lowman Road. The pullout is approximately 4 miles east of Banks. The mile marker may be missing, so count from mile markers 3 or 5. The same pullout was formerly used for Skinny Dipper Hot Springs (across the road, now permanently closed by the BLM due to visitor abuse and safety concerns).
Regional Context
The Banks-Lowman Highway follows the South Fork Payette River through a scenic canyon with numerous hot springs along the corridor. For visitors seeking hot springs near Banks, Kirkham Hot Springs (a developed Forest Service site with multiple pools, approximately 30 miles east) is the most popular option. Pine Flats Hot Springs (roadside, several miles east of Banks) is another accessible option. The road continues east to Lowman and connects to Highway 21 toward Stanley and the Sawtooth Valley, with additional hot springs along the way.
Suitability & Accessibility
Who Should Visit Bronco Billy Hot Spring
Bronco Billy Hot Spring is best suited for hot springs enthusiasts interested in the history and geology of the Banks-Lowman corridor rather than visitors seeking a comfortable soaking experience. The source pool is extremely hot and shallow, making comfortable soaking difficult. The 1996 mudslide permanently altered the spring, and the original comfortable pools have not recovered.
The roadside access makes the spring easy to reach with no hiking required. The pullout is accessible year-round, though winter conditions on the Banks-Lowman Road can be icy and challenging. The spring is clothing optional due to the undeveloped nature of the site. Visitors should set expectations accordingly, as this is a diminished version of a formerly popular soaking destination.
Accessibility at Bronco Billy Hot Spring
The spring is not wheelchair accessible. While it has roadside access, the ground around the spring is unimproved and the pool is on a hillside above the road. Those exploring natural hot springs Idaho offers along the Banks-Lowman corridor who want a reliable soaking experience should continue east to Kirkham Hot Springs or Pine Flats Hot Springs, both of which offer more comfortable and consistent soaking pools with established facilities and reliable temperatures.
Safety & Etiquette
Bronco Billy Hot Spring Safety Tips
Bronco Billy Hot Spring has extremely hot source water that can cause severe burns. Do not enter the source pool without testing the temperature first. The metal channel delivering hot water from the hillside source is dangerously hot. The shallow source pool has inconsistent temperatures and no reliable way to cool the water for comfortable soaking.
The 1996 mudslide history demonstrates the geological instability of the canyon walls in this area. During heavy rain or rapid snowmelt, mudslides remain a risk. Do not linger at the spring during heavy precipitation events. The pullout is on a busy highway with traffic passing at speed.
Road and Environmental Awareness
The Banks-Lowman Road can be icy and narrow in winter. Drive with caution. The South Fork Payette River below the spring is swift and cold. Do not attempt to cross the river or enter it near the spring. Rattlesnakes may be present on the hillside above the road during warmer months. Parking at the pullout is free but limited.
Leave No Trace
Pack out all trash. The former Skinny Dipper Hot Springs across the road was permanently closed due to visitor abuse. Help prevent similar closures by treating all hot springs responsibly. Follow all Boise National Forest regulations. The nearest medical facilities are in Boise, approximately one hour west. Cell service is limited along the Banks-Lowman corridor. Carry a first aid kit and inform someone of your travel plans when exploring this area.
