Castle Hot Springs

Yavapai County, Arizona · Near Black Canyon City
33.9880°N, 112.3620°W · 2,120 ft
115°F 60°F air · Good soaking weather 2,120 ft Short Walk Camping nearby (12.6 mi)
Aerial view of the ground around Castle Hot Springs LiDAR bare-earth view of the same ground around Castle Hot Springs
Aerial LiDAR bare earth

Drag the handle to compare the two views. The orange dot marks the spring, in a frame about three quarters of a mile wide.

Castle Hot Springs is a historic resort in the Hieroglyphic Mountains of Yavapai County, about fifteen miles from Black Canyon City, and it is hot in earnest, right around 115 degrees at the source by the record. Wikipedia notes the resort has recently been restored and is on the National Register of Historic Places. The access line is blank, and so is the landowner. A 1979 chemistry sits in the USGS record.

Location

Castle Hot Springs Road runs within a couple hundred yards of the spring, so reaching it takes a short walk at most. Low desert, around two thousand feet, with mild winters and almost no snow. Across a year the thermometer averages close to seventy. Horsethief Cabin, a dozen or so miles away, is as close as camping gets in the record. The 1979 water sample shows a slightly alkaline pH.

Go in winter if you can, December through February per the record. The water is above 110, so test before stepping in and assume the source is hotter than any pool. The spring sits on a resort, so treat access as the resort's call and check ahead. For camping the record gives Horsethief Cabin, a drive away. No fee information is listed.

History of Castle Hot Springs

Wikipedia describes Castle Hot Springs as a recently restored historic resort listed on the National Register of Historic Places, set within the Hieroglyphic Mountains. The USGS sampled the water in June 1979.

Terrain

Aircraft with laser scanners measured this ground to within inches. The scan strips out trees and buildings, leaving the bare shape of the land around Castle Hot Springs.

Setting
Canyon floor
Steep ground climbs away on both sides of the spring.
Highest ground nearby
254 ft above the spring
Within a quarter mile, to the north
Cross-section through the spring

A slice through the ground from northwest to southeast, about 0.6 miles end to end.

Elevation data: USGS 3D Elevation Program. Aerial imagery: USGS The National Map. Public domain.

Heat Below
68 milliwatts per square meter of heat flow

That's close to the US average of 65. It's higher than at 4% of the springs on this site.

Heat flow measures the warmth working its way up through the ground from deep inside the earth. Where it runs high, rain and snowmelt that seep down through cracks in the rock come back up hot.

Heat flow estimate: Stanford Thermal Earth Model (Aljubran & Horne, 2024), CC BY 4.0.

Monthly Climate
50°
Jan
53°
Feb
59°
Mar
66°
Apr
75°
May
85°
Jun
89°
Jul
87°
Aug
82°
Sep
70°
Oct
59°
Nov
50°
Dec
Annual Precip: 13.0 in Annual Snow: 2.8 in
Best Time to Visit
January Air 50°F · Water 115°F · +65° contrast
December Air 50°F · Water 115°F · +65° contrast
February Air 53°F · Water 115°F · +62° contrast
January offers 39°F more contrast than July
Current Conditions
60°F
WSW 3.6 mph 93% Good soaking weather
Tuesday 93° Low 77° Chance Showers And Thunderstorms 39% precip
Spring is +22° warmer
Wednesday 89° Low 75° Showers And Thunderstorms Likely 60% precip
Spring is +26° warmer
Thursday 91° Low 74° Chance Showers And Thunderstorms then Mostly Sunny 32% precip
Spring is +24° warmer
Friday 96° Low 76° Sunny 3% precip
Spring is +19° warmer
Saturday 98° Low 77° Sunny 4% precip
Spring is +17° warmer
Water Chemistry Sampled 1979-06-22

The water at Castle Hot Springs is slightly alkaline (pH 7.7). It is notably rich in sulfate (traditionally used for skin conditions and inflammation) and chloride (natural antiseptic with skin health benefits).

pH 7.7 Slightly Alkaline
pH influences mineral absorption through skin
Calcium 29 mg/L
May support bone density and joint health
Magnesium 2 mg/L
Known for muscle relaxation and stress relief
Sodium 220 mg/L
Supports circulation and skin hydration
Sulfate 220 mg/L
Traditionally used for skin conditions and inflammation
Chloride 140 mg/L
Natural antiseptic with skin health benefits
Where to Stay

Some links are affiliate links. We may earn a commission at no extra cost to you.

Nearby Camping
Horsethief Cabin 12.6 mi away

Overview Horsethief Cabin is situated in a clearing of Ponderosa pines at an elevation of over 6,000 feet in the Bradshaw Mountains of the Prescott National Forest. The original cabin was built in 1939 as quarters and a staging area for Forest Service crews charged with protecting the southern end of the Bradshaw Mountains against wildfires. The cabin was remodeled and modernized over the years, but eventually fell into disuse by the 1980s. The historic structure now enjoys a second life as a...

Reservable Yes
Reserve on Recreation.gov →
Temperature
115°F
Warm Hot Boiling
Water Temp 115°F (46°C)
Avg Air Temp 69°F
Above Ambient +46°F
Good soaking conditions September
Access
Road Access Short Walk
Nearest Road Castle Hot Springs Road
Distance to Road 0.2 mi
Frequently Asked Questions
What is the water temperature at Castle Hot Springs?
Castle Hot Springs has a water temperature of 115°F (46°C). This is considered a hot spring, well above body temperature.
Where is Castle Hot Springs located?
Castle Hot Springs is located in Yavapai County, Arizona at 2,120 feet elevation, near Black Canyon City. Coordinates: 33.9880°N, 112.3620°W.
How do I get to Castle Hot Springs?
Castle Hot Springs has Short Walk road access, with the nearest road being Castle Hot Springs Road (0.2 mi from the road).
Can I camp near Castle Hot Springs?
Yes, Horsethief Cabin is located nearby (12.6 miles away).
What minerals are in the water at Castle Hot Springs?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 7.7 (slightly alkaline).
Is it safe to soak at Castle Hot Springs?
With care. At 115°F Castle Hot Springs is hot enough to need short sessions, fifteen to twenty minutes, and plenty of water. Enter slowly and get out if you feel light-headed.
Sources: USGS NWIS, Wikipedia