Quick FactsOverview
About Nimrod Hot Springs
Nimrod Hot Springs, Montana is a free, undeveloped natural warm spring pool on private land near Bryne in Granite County, approximately 35 miles east of Missoula off Interstate 90 at the Bearmouth exit, mile marker 138. A large, deep pool of crystal-clear blue water is fed by a geothermal spring that cascades down a rock wall, creating a visually striking natural feature that draws visitors from Missoula and the region. The water maintains approximately 70 degrees Fahrenheit year-round - comfortable for swimming in warm weather and noticeably warm on cool days in spring and fall.
The pool is deeper than most natural springs in Montana, with enough depth for swimming and for the site's most notable feature: an underwater cave accessible by swimming through a submerged passage beneath the rock face. A rope is available at the pool for exiting after a dive. The private landowners allow public access as a courtesy at no charge. No facilities are present: no restrooms, no changing areas, and no trash bins. Visitors must pack out everything they bring.
For those seeking free hot springs Montana accessible by a short walk from a major interstate, Nimrod is one of the most accessible wild soaking sites in western Montana, roughly 35 minutes east of Missoula on I-90.
Location & Access
Getting to Nimrod Hot Springs
Nimrod Hot Springs is reached from Interstate 90 at exit 138, the Bearmouth exit, approximately 35 miles east of Missoula. After taking the exit, head north on Drummond Frontage Road. Do not cross the railroad tracks; instead, turn around and follow the frontage road in the opposite direction. Continue until you reach a sign for Fishing Access on the left and turn down that road to reach an informal parking area in approximately 1,500 feet. The parking area is unpaved with no facilities.
From the parking area, walk west with the interstate on your left for approximately half a mile along the old highway surface and frontage road. You will pass a Do Not Trespass sign that applies to the adjacent private property to the right, a closed gate, a cattle guard, a house, and a barn while following the established access route. Continue along the fence line. When you see a concrete road divider placed along the fence, this marks the access point: walk under or through the fence and follow the well-defined gravel path to the spring. The pool is visible from a short distance once you pass the fence.
For those seeking hot springs near Missoula Montana accessible without a long detour, Nimrod is the most direct wild spring from the city, about a 35-minute drive east on I-90. No hiking experience or special gear is needed for the walk in. The path can be muddy in spring or icy in winter - wear appropriate footwear. No camping is permitted at the site.
Suitability & Accessibility
Who Can Visit Nimrod Hot Springs
Nimrod Hot Springs suits casual swimmers, day-trippers from Missoula, families with older children, and visitors seeking a free natural experience without resort facilities. At 70 degrees the water is best visited from late spring through early fall when air temperatures make it enjoyable. Winter visits are possible but the water will not provide warmth in cold conditions, and the access path may be icy.
The pool's depth makes it suitable for swimming. The underwater cave requires swimming through a submerged passage and is recommended only for strong, experienced swimmers. Scuba gear helps with visibility inside. Cliff jumping is practiced by visitors given the depth but carries inherent risk; check the pool floor and depth at the jump point first. No lifeguard is ever present.
Free hot springs Montana sites are rare; Nimrod fills that role near Missoula, making it a popular local spot in summer. Clothing is optional at this undeveloped site. Young children are welcome but require close supervision given the depth and absence of any safety infrastructure.
The site is not wheelchair accessible. The half-mile walk is on an uneven old road surface. No facilities exist on site: no restrooms, no changing areas, no shade, and no trash bins. Visitors must be self-sufficient and pack out all waste. Camping is not permitted.
Safety & Etiquette
Safety at Nimrod Hot Springs
Nimrod Hot Springs warrants mindfulness as an unmanaged natural site with no supervision, no facilities, and a pool deep enough to pose a drowning risk. No lifeguard is ever present. Every person who enters the water is responsible for their own safety and for supervising children. Do not swim alone.
The underwater cave is the primary hazard for those who choose to explore it. Swimming through the submerged passage requires breath-holding in a confined space with limited visibility and some disorientation risk. Attempt this only if you are a strong, experienced swimmer. Scuba gear helps with visibility. A rope at the surface helps with exiting after a dive. Cliff jumping carries risk from unseen underwater obstructions; check depth at the jump point before jumping and never jump headfirst.
The site is on private land. The landowners allow access as a courtesy - respect all boundaries, stay on the established route, and do not enter adjacent private property. Take all trash out. If access is ever denied by the landowner, do not attempt to enter. The access path passes a Do Not Trespass sign that applies to adjacent property to the right, not to the spring access route itself.
The path can be icy or muddy by season; wear footwear with grip. No cell service may be available near the I-90 canyon. Inform someone of your plans before visiting. The nearest emergency services are in Missoula, approximately 35 miles west, and Drummond, approximately 20 miles east. Carry a first aid kit.
