Kelly Warm Spring
By the HotSpringsFind editorial team · How we compile records · Reviewed September 2026
A roadside ~80F warm spring inside Grand Teton National Park, ~1 mi NE of Kelly on Gros Ventre Road — technically enterable but NPS says entering is 'not recommended': testing found E. coli above EPA limits plus brain-eating amoeba Naegleria fowleri, salmonella and tapeworms, and the pool is choked with decades of dumped invasive aquarium fish.
Field notes — checked September 2026
- Hazard: Naegleria fowleri brain-eating amoeba + E. coli/salmonella/tapeworms — do not submerge head or enter
- Hazard: Invasive-species contaminated water
- Hazard: Bison/elk near the pool in spring — wildlife distance rules
- Hazard: Winter road conditions on Gros Ventre Rd beyond Kelly
- NPS explicitly: 'Entering the warm spring is not recommended' — water contains E. coli exceeding EPA limits, salmonella, tapeworms, and Naegleria fowleri (brain-eating amoeba; nearly always fatal if water enters the nose)
- Soaking is discouraged but NOT technically prohibited (unlike Huckleberry/Polecat springs in the adjacent Rockefeller Parkway, where entry has been illegal since 2014) — nonetheless treat this as a look-don't-soak site
- Decades of illegal aquarium dumping filled the spring with goldfish, swordtails, cichlids, guppies, madtoms and bullfrogs; NPS ran a pesticide treatment Aug 2018 and releasing aquarium animals is a Class B misdemeanor
- Grand Teton NP entrance fee applies; restroom at site; families picnic on the grassy meadow; bison and elk frequent the area in spring
- The paved section of Gros Ventre Rd to Kelly is maintained year-round (Kelly is a residential community); the gravel road beyond into the Gros Ventre valley is seasonal — check current park road status in winter
- NO overnight parking/camping at the spring — Gros Ventre Campground ~3 mi away
Current status
A roadside ~80F warm spring inside Grand Teton National Park, ~1 mi NE of Kelly on Gros Ventre Road — technically enterable but NPS says entering is 'not recommended': testing found E. coli above EPA limits plus brain-eating amoeba Naegleria fowleri, salmonella and tapeworms, and the pool is choked with decades of dumped invasive aquarium fish.
Checked September 2026 · verified against an official source · 5 sources ↓
About this spring
VIEW-ONLY — not a soaking destination. Warm spring pool inside Grand Teton National Park about a mile northeast of Kelly, ringed by meadow where bison and elk graze. Averages only ~77-80°F — a warm spring, not a hot soak. Formerly a popular swimming hole, but NPS now advises against entering the water due to documented high E. coli and Naegleria fowleri. Fee: Grand Teton NP entrance fee applies. NPS advises AGAINST entering — E. coli and brain-eating amoeba documented. Do not release fish. View-only recommended.
Kelly Warm Spring is a roadside warm spring in Grand Teton National Park about a mile northeast of Kelly, a town founded by William Kelly, who built a sawmill there in 1907. The spring holds near 80°F year-round — warm enough to green up the surrounding meadow early, drawing bison and elk in spring, but well below soaking temperature. NPS explicitly does not recommend entering the water, citing high E. coli levels and the presence of Naegleria fowleri, the amoeba behind a nearly always fatal brain infection.
The spring is also an ecological management problem: decades of illegal aquarium dumping established populations of swordtails, convict cichlids, guppies, goldfish, and tadpole madtoms that spread into Savage Ditch and Ditch Creek and prey on native fish including Snake River cutthroat trout. The park evaluated netting, trapping, and electrofishing before selecting rotenone — a short-lived, low-toxicity pesticide used elsewhere in the Greater Yellowstone Ecosystem — to eliminate the invasives, with monitoring and restocking of native fish as needed.
Directions & trailhead access
Access is restricted; do not use historical directions to plan a visit.
Wyoming geothermal context
Wyoming holds the planet's densest geothermal field in Yellowstone — nearly all of it legally protected and off-limits to soaking. The visitable thermal water is outside the park: Thermopolis' free state bathhouse, river-edge springs along the North Platte, and scattered backcountry seeps in grizzly country where bear-aware travel is mandatory.
What a developed site means here
A developed site sits between primitive and resort: improved soaking infrastructure — built tubs, decks, stairs, sometimes changing rooms or vault toilets — often run by a land trust, nonprofit, or small operator. Expect modest fees or donation requests, posted etiquette rules, and more predictable conditions than a wild pool.
Fact sheet
| Source temp (historical) | 80°F |
|---|---|
| Trail access | Recorded coordinates — access unverified |
| Access fee | Fees reported |
| Geothermal data reference | NOAA Thermal Springs List (1980 archive) |
| Check land status | NPS — Kelly Warm Spring (official place page) |
Kelly Warm Spring FAQ
Is Kelly Warm Spring open right now?
A roadside ~80F warm spring inside Grand Teton National Park, ~1 mi NE of Kelly on Gros Ventre Road — technically enterable but NPS says entering is 'not recommended': testing found E. coli above EPA limits plus brain-eating amoeba Naegleria fowleri, salmonella and tapeworms, and the pool is choked with decades of dumped invasive aquarium fish. (Status verified against an official source, last checked September 2026.)
Can I soak at Kelly Warm Spring?
A roadside ~80F warm spring inside Grand Teton National Park, ~1 mi NE of Kelly on Gros Ventre Road — technically enterable but NPS says entering is 'not recommended': testing found E. coli above EPA limits plus brain-eating amoeba Naegleria fowleri, salmonella and tapeworms, and the pool is choked with decades of dumped invasive aquarium fish.
Where can I check access to Kelly Warm Spring?
Check NPS — Kelly Warm Spring (official place page): https://www.nps.gov/places/000/kelly-warm-spring.htm
Sources & references
- NPS — Kelly Warm Spring (official place page) — official · 2026-09
- Jackson Hole News&Guide — Kelly spring contains brain-eating amoeba — news · 2018
- NPS Park Planning — Restoring Natural Conditions to Kelly Warm Spring — official · 2018
- Hot Springs Guides — Kelly Hot Springs Wyoming — community · 2026-09
- SoakingSprings — Kelly Warm Spring listing — community · 2026-05
Details above were verified against the named sources on their listed dates — conditions change, so recheck before traveling. · How we verify our data · Report a correction