Gigantic Warm Springs
By the HotSpringsFind editorial team · How we compile records · Reviewed September 2026
Gigantic Warm Springs is a developed hot spring listed near Lewistown, Montana. Reported soak temperature: 68°F. See the visit fact sheet.
Current status
Private-ranch family swimming venue ~14 mi north of Lewistown on MT-81 — the Vanek family's Paradise Ranch has charged a few dollars admission since the 1940s for a ~100-yard natural pool fed by a constant 68F spring flowing ~50,000 gal/min (billed as the world's largest warm spring); open roughly June 1 to Labor Day, noon-9 pm daily, lifeguarded, with picnic tables and a wading pool — closed the rest of the year.
verified on the operator’s site · 6 sources ↓
Staying overnight?
A town night before or after a central Montana trip.
Lewistown is about 10 mi from the spring (straight line).
We may earn a commission from bookings through these links, at no extra cost to you.
Before you go
- Status: Open — last verified below — confirm via HiddenMT — Gigantic Warm Spring venue page (season June 1-Labor Day, 12-9 PM, admission tiers, Vanek Paradise Ranch).
- Cost: Reported $3 — confirm current rates before visiting.
- Getting there: No verified hike distance on record — confirm the route and road conditions.
- Water: Reported soak temperature 68°F — always test the water before entering.
- Rules: Reported clothing required; pets reported not allowed — confirm current rules.
- Conditions: check weather, fire closures, and land-manager alerts the week you go — mountain access changes seasonally.
- Reservations/permits: None — pay admission at the gate or honor box; check the Vanek family's 'Gigantic Warm Springs' Facebook page for each season's opening date.
- Best time to go: Weekday afternoons early in the season (June) or late August after crowds thin; hot July weekends draw Lewistown families.
- Clothing reality: Family swim venue — regular swimwear required; this is not a soaking/clothing-optional site.
- Kids: Allowed.
- Cell service: spotty — download maps and tell someone your plan.
- Accessibility: Short flat walk from the spacious unpaved parking lot to the swim area — among the easiest 'springs' to reach; natural pool edges are informal but there are decks and gravel surfaces.
- SEASONAL ONLY — opens ~June 1 (weather-dependent, can shift a week or two) and closes Labor Day Monday; outside that window there is no access
- Hours are 12 PM-9 PM daily in season; honor box collects admission when unattended ($5 adult / $3 ages 6-13 / free under 5 — last published 2022; bring small bills, confirm on their Facebook page)
- Water is a constant 68F — refreshing in July heat but this is NOT a hot spring soak; cold by hot-springs standards
- NO DOGS — you will be asked to leave with no refund (working ranch rule)
- Day use only — no overnight camping; pack out all garbage
- Stay out of the waterfall area and be aware of currents in the outflow creek; owners reserve right to refuse entry (private property, working ranch)
- Main pool is up to ~14 ft deep — strong natural flow; roped wading pool on the east end for small kids; lifeguard on duty during open hours
- Easy access: paved US-191 north ~9.5 mi, left on MT-81 ~3.5-5 mi, right at the big Warm Springs sign onto Warm Spring Lane ~1 mi; any vehicle fine
- Hazard: Deep natural pool (~14 ft) with spring flow currents — swim ability required despite lifeguard
- Hazard: Waterfall and outflow-creek currents off-limits
- Hazard: 68F water — chill risk on cool days
- Hazard: Seasonal window only — arriving Sept-May means a locked gate
About this spring
The 'World's Largest Warm Spring' — ~50,000 gpm of constant 68°F water forming a 100-yard natural swimming basin on a family ranch 14 mi north of Lewistown; lifeguard, decks, picnic tables and camping. A beloved central-Montana summer institution — warm, not hot. Fee: Small entrance fee (~$3-5) at private ranch. 68°F is a warm swim, not a hot soak; primarily summer (Jun-Aug).
Gigantic Warm Spring bills itself as the world's largest warm spring and the third-largest natural spring by volume, discharging an average of about 50,000 gallons a minute at a constant 68°F. It rises on the Vanek family's Paradise Ranch between the North and South Moccasin Mountains, roughly 14 miles north of Lewistown in Fergus County. In the late 1930s the spring supplied a power and water plant for the Kendall Gold Mine; the senior Vanek began admitting swimmers for a small fee during the Depression, and the family has operated it as a community swimming spot since 1940.
The natural basin spans about 100 yards and can hold up to 200 swimmers, with a roped-off wading pool for children, a lifeguard on duty during all open hours, decks, picnic tables, volleyball nets and horseshoe pits. It is a summer-only operation — approximately June 1 through Labor Day, noon to 9 p.m. — and dogs and overnight camping are not permitted on site.
Directions & trailhead access
749 Warm Spring Lane, Lewistown — ~14 mi north of town, signed.
Montana geothermal context
Montana's springs cluster around Yellowstone's northern margin and along basin-range faults in the western half of the state. A large share of named sites sit on private ranch land or have limited legal access, which is why status notes matter here. Cold winters and heavy spring runoff reshuffle riverside pools every year.
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.
Best time to visit
Year-Round (Best: May – October)Pool temperatures and access can change with weather and season. Outdoor ambient temperatures fluctuate significantly across Montana. Late spring through autumn offers the most comfortable road access.
Fact sheet
| Reported soak temp | 68°F |
|---|---|
| Source temp (historical) | 68°F |
| Trail access | Recorded coordinates — access unverified |
| Access fee | Reported $3 — verify |
| Clothing policy | Reported clothing required |
| Pet policy | Reported no pets |
| Geothermal data reference | NOAA Thermal Springs List (1980 archive) |
| Check land status | HiddenMT — Gigantic Warm Spring venue page (season June 1-Labor Day, 12-9 PM, admission tiers, Vanek Paradise Ranch) |
Gigantic Warm Springs FAQ
Is Gigantic Warm Springs open right now?
Private-ranch family swimming venue ~14 mi north of Lewistown on MT-81 — the Vanek family's Paradise Ranch has charged a few dollars admission since the 1940s for a ~100-yard natural pool fed by a constant 68F spring flowing ~50,000 gal/min (billed as the world's largest warm spring); open roughly June 1 to Labor Day, noon-9 pm daily, lifeguarded, with picnic tables and a wading pool — closed the rest of the year. (Status verified on the operator’s site.)
Is Gigantic Warm Springs free?
Gigantic Warm Springs is listed with reported fees near Lewistown. Fees are reported; confirm admission, parking and permit costs with the site manager.
What temperature is Gigantic Warm Springs?
Gigantic Warm Springs has a reported soak temperature of 68°F and a historical source temperature of 68°F in survey records. Historical data may not reflect current conditions — always test water before entering.
Is Gigantic Warm Springs clothing optional?
Gigantic Warm Springs is listed as swimsuit-required in directory records. Confirm current rules before visiting, as policies change.
How do you access Gigantic Warm Springs?
Gigantic Warm Springs is on public land — verify current road access, fees and rules with the land manager before visiting.
Where to stay in Lewistown
A town night before or after a central Montana trip. Check the privately managed spring’s current access.
Lewistown is about 10 mi from the spring (straight line).
We may earn a commission from bookings through these links, at no extra cost to you.
Sources & references
- HiddenMT — Gigantic Warm Spring venue page (season June 1-Labor Day, 12-9 PM, admission tiers, Vanek Paradise Ranch) — operator · 2025
- Montana Hot Springs Facebook post relaying landowner rules (no dogs, day use only, honor box, $5/$3 admission, stay out of waterfall) — operator · 2022-06
- KBZK — 'Gigantic Warm Spring popular spot for Lewistown locals' (68F year-round, Vanek family since early 1940s, pricing) — news · 2022
- Enjoy Lewistown (chamber) — Warm Springs listing (fees, no dogs, directions, phone 406-538-9825) — operator · 2025
- Central Montana blog — Swimming at Gigantic Warm Springs (Facebook page is the way to confirm opening dates) — community · 2023
- Hot Springs Guides — Gigantic Warm Spring (lifeguard, wading pool, ~100-yd swim area, history incl. Kendall Gold Mine plant) — community · 2025
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
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