Boulder Creek Spring
Boulder Creek Spring delivers 82-degree Fahrenheit water just 52 feet from Boulder Creek Road near McCall, with an exceptionally high pH of 9.9, among the most alkaline thermal springs anywhere in Idaho. At 3,080 feet elevation, it sits lower than most Idaho springs, in the deep canyon of the South Fork Salmon River drainage.
The spring emerges in a steep, heavily forested canyon in Valley County. Thick stands of ponderosa pine and cedar crowd the road, and Boulder Creek tumbles nearby over moss-covered rock. Despite the relatively low elevation, annual snowfall exceeds 150 inches, and the narrow canyon holds shade and moisture. The warm water seeps from fractured rock right at road level, and the alkaline chemistry leaves a slick mineral film on surrounding stones.
The extreme alkalinity, pH 9.9, reflects extensive water-rock interaction deep within the Idaho Batholith's granitic mass. As water percolates downward through fractures, it dissolves silica and sodium while shedding calcium, producing the sodium-dominated, calcium-depleted chemistry measured by the USGS. The low chloride at 4.4 mg/L suggests minimal mixing with shallower groundwater, pointing to a relatively isolated deep flow path.
The spring is roadside on Boulder Creek Road with no walking required. Grouse Campground, 18 miles away on Goose Lake near McCall, has reservable sites with canoeing and fishing. Cell service is limited in the canyon. The road may be impassable during spring snowmelt or after heavy rain. Bring drinking water, as the spring water is not potable.
Is Boulder Creek Spring worth visiting?
Best for
- Warm-water soaking
- Easy day trips
- Overnight camping trips
The water at Boulder Creek Spring is alkaline (pH 9.9).
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Overview Grouse Campground is located just 16 miles from McCall, Idaho, on the shores of Goose Lake. Visitors enjoy canoeing, fishing and horseback riding. Once on-site, you may be able to pay for your campsite(s) by scanning a QR code using the Recreation.gov mobile app, and the Scan and Pay feature. If this option is available, you will need to first download the free Recreation.gov mobile app https://www.recreation.gov/mobile-app prior to your arrival as some remote areas have limited or...