Photo by Ali Soheil on Pexels
🇺🇸 USA · Custer County, Idaho
♨ Temperature
40°C
⛰ Altitude
1800 m
⚗ pH
7.6
💧 TDS
580 mg/L
🌊 Flow rate
10 L/s
📅 Established
Known since early settlement era; BLM-managed since 1990s
✓ Verified on 2026-07-22
Maple Grove Hot Springs occupies a quiet cottonwood-shaded canyon in the high desert of Custer County, Idaho, a short distance from the Salmon River in the remote mountain interior of the state. The springs emerge at around 40°C from the base of a low basalt cliff and feed a small network of developed soaking pools and a roofed bathhouse. The Bureau of Land Management (BLM) manages the site as a fee-based primitive recreation area, maintaining basic infrastructure — pools, changing facilities, and a fee station — while keeping the character deliberately rustic. The surrounding landscape is the Salmon River Mountains: one of the largest roadless wilderness areas in the contiguous United States, dominated by ponderosa pine, big sagebrush, and the dramatic canyon systems carved by the Salmon River and its tributaries. The Frank Church–River of No Return Wilderness, the largest designated wilderness area in the lower 48 states at over 2 million acres, begins just north of Custer County. Maple Grove's appeal is precisely its remoteness and simplicity — it draws visitors willing to travel significant distances from Challis or Sun Valley for an unhurried, low-density backcountry soaking experience that requires no advance reservation.
| Sodium | 112 mg/L |
| Bicarbonate | 282 mg/L |
| Sulphate | 68 mg/L |
| Calcium | 44 mg/L |
| Silica | 38 mg/L |
| Magnesium | 16 mg/L |
Custer County and the Salmon River corridor sit within the ancestral territory of the Agaidika (Salmon River Lemhi Shoshone) people, whose name means 'Salmon Eaters' and reflects their deep relationship with the river system. Sacajawea, who guided the Lewis and Clark Expedition, was born in this region. The Shoshone-Bannock Tribes of Fort Hall Reservation maintain cultural and treaty connections to the Salmon River Mountains. The Frank Church Wilderness that surrounds this region is one of the most significant protected Indigenous cultural landscapes in the American West.
The Salmon River — the 'River of No Return' — became iconic in American frontier mythology partly because the canyon's current was so powerful that boats could travel downstream but could not return upstream. Lewis and Clark attempted the Salmon River canyon route in 1805 and were forced to abandon it. The Frank Church Wilderness that bears the name of Idaho's famous conservationist senator encompasses a scale of genuine roadless terrain almost without parallel in the lower 48 states.
Maple Grove is managed by the BLM Challis Field Office as a low-impact recreation site. Access fees support maintenance of the primitive pool infrastructure. The surrounding Salmon River Mountains contain one of the best-preserved examples of intact Great Basin sagebrush steppe ecosystem, and the Frank Church Wilderness immediately to the north is managed under the strictest federal wilderness protection standards.
Phone+1 208-879-6200
Websitewww.blm.gov/office/challis-field-office
AddressCuster County, ID 83201, USA (BLM Challis Field Office)