At 151°F, the source water at Roystone Hot Springs is hot enough to cause burns. Some hot springs this hot have cooler side pools or downstream areas suitable for soaking — always test the water temperature before entering.
Roystone Hot Springs reaches a scalding 151 degrees Fahrenheit in Gem County, creating a 98-degree differential with the average air temperature. That extreme heat makes this one of the hottest springs in the Emmett area, visible by its steam plume rising near East Black Canyon Highway.
The spring sits at 2,530 feet elevation in the low foothills east of Emmett, where the landscape is drier and more open than Idaho's mountain interior. Annual precipitation runs about 21 inches with modest snowfall of 33 inches. The terrain is characterized by rocky slopes and sparse vegetation. A short walk of roughly 540 feet from the highway leads to the source, where the water is far too hot to touch without significant cooling.
History of Roystone Hot Springs
The 151-degree temperature indicates deep fault-controlled circulation, likely along the western margin of the Idaho Batholith where it meets the older metamorphic rocks of the Black Canyon area. The extreme heat and low elevation combine to produce one of the largest thermal-to-ambient differentials in Idaho. Development of the nearby highway corridor has made the spring easily observable but has not altered the geothermal source.
Do not enter the source water. At 151 degrees, it causes severe burns on contact. Any soaking requires substantial mixing with cold creek water downstream. The spring is a short walk from East Black Canyon Highway near Emmett. The nearest reservable campground is Shafer Butte, roughly 29 miles away near Bogus Basin. This is a look-and-observe feature for most visitors.
Is Roystone Hot Springs worth visiting?
Best for
Observing powerful hot springs
Overnight camping trips
Not ideal for
Casual soaking
Roystone Hot Springs is well suited for observing powerful hot springs and overnight camping trips.
Monthly Climate
30°Jan
36°Feb
44°Mar
50°Apr
60°May
69°Jun
79°Jul
78°Aug
68°Sep
53°Oct
40°Nov
30°Dec
Annual Precip: 20.6 inAnnual Snow: 32.9 in
Best Time to Visit
JanuaryAir 30°F · Water 151°F · +121° contrast
DecemberAir 30°F · Water 151°F · +121° contrast
FebruaryAir 36°F · Water 151°F · +116° contrast
January offers 49°F more contrast than July
Nearby Camping
Shafer Butte17.7 mi away
Overview
Shafer Butte is located atop the scenic Boise Ridge Mountains, near Bogus Basin Mountain Recreation Area, at an elevation of 7,000 feet. Visitors enjoy hiking and biking on various trails in the surrounding area, and simply relaxing and taking in the area's beautiful views.Recreation
Popular activities in the area include hiking and mountain biking, the Mores Mountain Trail begins in the campground. This 2-mile interpretive nature trail is family friendly. Facilities
Shafer Butte con...
What is the water temperature at Roystone Hot Springs?
Roystone Hot Springs has a water temperature of 151°F (66°C). This is considered a hot spring, well above body temperature.
Where is Roystone Hot Springs located?
Roystone Hot Springs is located in Gem County, Idaho at 2,530 feet elevation, near Emmett. Coordinates: 43.9510°N, 116.3530°W.
How do I get to Roystone Hot Springs?
Roystone Hot Springs has Short Walk road access, with the nearest road being East Black Canyon Highway (0.1 mi from the road).
Can I camp near Roystone Hot Springs?
Yes, Shafer Butte is located nearby (17.7 miles away).
Is it safe to soak at Roystone Hot Springs?
The water at Roystone Hot Springs reaches 151°F, which can cause severe burns. Do not enter the source pool directly — look for cooled side pools or downstream areas where the water has cooled to a safe temperature. Access may be on private land or unconfirmed — verify current conditions before visiting. Always tell someone your plans before visiting remote hot springs.
Is Roystone Hot Springs crowded?
Roystone Hot Springs sees varying levels of visitors depending on the season and day of the week.
What should I bring to Roystone Hot Springs?
Essentials for Roystone Hot Springs: swimsuit, towel, water bottle, camping gear, a trash bag to pack out what you pack in. The water is over 110°F — test the temperature before entering and watch for scalding near the source.