Mr. Bubbles (Ferris Fork)
By the HotSpringsFind editorial team · How we compile records · Reviewed September 2026
Mr. Bubbles (Ferris Fork) is a primitive hot spring listed near Ashton, ID (Bechler trailhead), Wyoming. Reported soak temperature: 104°F. See the visit fact sheet.
Current status
Famous mixed-temperature backcountry soaking pool on the Ferris Fork in Yellowstone's Bechler corner; roughly a 13.5-16 mile hike from Bechler Ranger Station, best done as an overnight with a hard-to-get backcountry permit, and legal only because the soak spot is creek-mixed rather than purely thermal water.
Checked September 2026 · verified against an official source · 7 sources ↓
Before you go
- Status: Reservation or permission required — confirm via NPS Yellowstone — Safety (thermal areas / soaking rule).
- Cost: Fees reported — confirm current rates before visiting.
- Getting there: No verified hike distance on record — confirm the route and road conditions.
- Water: Reported soak temperature 104°F — always test the water before entering.
- Rules: Clothing policy unknown — verify locally; 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: Yellowstone backcountry permit via Recreation.gov permit #4675323; early-access lottery recommended for Bechler campsites; pick up in person at Bechler Backcountry Office (open mid-June to mid-Oct, 8am-4:30pm) or other backcountry office; non-peak season via Central Backcountry Office 307-344-2160.
- Booking: Reservation required.
- Best time to go: Late August through September: fords lower, mosquitoes gone, before the road/season closes. Avoid June-July (flooded meadows, mosquitoes, swollen fords).
- Clothing reality: Swimsuits customary; remote backcountry. NPS regulation prohibits bathing in water 'entirely of thermal origin' — the soakable pool is legal only because creek water mixes in. Neighboring pure thermal vents are strictly off-limits and deadly.
- Kids: Allowed.
- Cell service: none — download maps and tell someone your plan.
- Accessibility: Strenuous wilderness backpacking only — no day-hike practicality, no facilities.
- BACKCOUNTRY PERMIT REQUIRED for overnight (recreation.gov; peak season May 15-Oct 31, early-access lottery — Bechler is one of the park's high-demand areas); $10 reservation + $5/person/night; convert to permit at a backcountry office within 2 days of trip start
- Soaking legality is the gray area: NPS allows bathing only where hot-spring water flows into an existing stream — Mr. Bubbles qualifies (thermal vents + cold Ferris Fork mixing); bathing in purely thermal water is illegal. Ranger interpretation has varied — confirm at Bechler Backcountry Office
- ~32-mile round trip as a hike — realistically a 2-3 day backpack; nearest campsite Ferris Fork 9D1
- Serious thermal hazard: boiling fumarole feeds the pool and scalding vents surround it; temps vary step to step — probe carefully, stay in the creek-mixed pool
- Grizzly bear country — food storage rules enforced; bear spray essential
- Bechler Meadows floods and mosquitoes are brutal June-early Aug; multiple river fords can be dangerous in high water
- Cave Falls Road (from Ashton, ID) is gravel and closed to vehicles roughly Nov-late May
- Pets prohibited in Yellowstone backcountry
- Hazard: Scalding/boiling thermal vents adjacent to the soaking pool
- Hazard: River fords (Bechler River, Ferris Fork) dangerous in high water
- Hazard: Grizzly bears
- Hazard: 32+ miles of remote trail — self-reliance required
- Hazard: Acidic/alkaline thermal water off-trail
About this spring
One of very few legal soaking spots in Yellowstone National Park: thermal water wells into the cold Ferris Fork of the Bechler River in the remote Bechler backcountry, forming a ~15-ft-wide mixing pool named for gas bubbling through its center. NPS permits soaking only where thermal water has already mixed with stream water — entering thermal features themselves is illegal and dangerous. Fee: Yellowstone NP entrance fee + backcountry permit for overnight. Backcountry permit required. Bear country; thigh-deep river fords; severe mosquitoes. Surrounding thermal features are scalding — soak only in the mixing pool.
Mr. Bubbles sits in Yellowstone's remote Bechler backcountry, where thermal water burbling up through the bed of the Ferris Fork — Backpacker magazine puts the inflow at about 110°F — mixes with cold creek water in a pool roughly 15 feet across and four feet deep. The steady stream of gas rising through the pool's center gives the soak its name. Because Park Service rules prohibit entering thermal features but permit bathing where hot spring runoff has already blended with stream flow, this is one of the only legal wild soaks in the park; the surrounding vents discharge scalding water and are strictly off-limits.
The approach is a committed backpacking trip: roughly 13.5 miles up the Bechler River Trail from the Bechler Ranger Station (reached via 26 miles of Cave Falls Road from Ashton, Idaho) to the Ferris Fork campsite 9D1, which books out early largely because of the spring, then a half-mile spur to the pool. Hikers continuing two miles up the Ferris Fork pass four waterfalls named by William Gregg in 1921 for Shoshone figures, including 33-foot Tendoy Falls. A Yellowstone backcountry permit is required for overnight stays.
Directions & trailhead access
Bechler Ranger Station via Cave Falls Road from Ashton, Idaho; hike ~13.5 miles up the Bechler River Trail to the Ferris Fork (campsite 9D1 area), then ~0.25-0.5 mi up the spur to the bubbling pool.
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 primitive site means here
Primitive springs have no facilities: no changing rooms, no trash service, often no maintained road to the pool. Expect natural rock or gravel bottoms, water temperature that varies by spot and season, and other visitors who may treat the site informally. Pack out everything you bring, test the water before entering, and leave the pool cleaner than you found it.
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 Wyoming. Late spring through autumn offers the most comfortable road access.
Fact sheet
| Reported soak temp | 104°F |
|---|---|
| Source temp (historical) | 110°F |
| Trail access | Recorded coordinates — access unverified |
| Access fee | Fees reported |
| Clothing policy | Unknown — verify locally |
| Pet policy | Reported no pets |
| Geothermal data reference | NOAA Thermal Springs List (1980 archive) |
| Check land status | NPS Yellowstone — Safety (thermal areas / soaking rule) |
Mr. Bubbles (Ferris Fork) FAQ
Is Mr. Bubbles (Ferris Fork) open right now?
Famous mixed-temperature backcountry soaking pool on the Ferris Fork in Yellowstone's Bechler corner; roughly a 13.5-16 mile hike from Bechler Ranger Station, best done as an overnight with a hard-to-get backcountry permit, and legal only because the soak spot is creek-mixed rather than purely thermal water. (Status verified against an official source, last checked September 2026.)
Is Mr. Bubbles (Ferris Fork) free?
Mr. Bubbles (Ferris Fork) is listed with reported fees near Ashton, ID (Bechler trailhead). Fees are reported; confirm admission, parking and permit costs with the site manager.
What temperature is Mr. Bubbles (Ferris Fork)?
Mr. Bubbles (Ferris Fork) has a reported soak temperature of 104°F and a historical source temperature of 110°F in survey records. Historical data may not reflect current conditions — always test water before entering.
Is Mr. Bubbles (Ferris Fork) clothing optional?
Directory records do not confirm the clothing policy at Mr. Bubbles (Ferris Fork) — verify current rules before visiting.
How do you access Mr. Bubbles (Ferris Fork)?
Mr. Bubbles (Ferris Fork) requires permission, a permit or advance booking — confirm the terms with the site manager before visiting.
Sources & references
- NPS Yellowstone — Safety (thermal areas / soaking rule) — official · 2026
- NPS Yellowstone — Beyond Roads End backcountry guide (soaking allowed only where springs mix into existing water) — official · 2020
- Recreation.gov — Yellowstone Backcountry Permits — official · 2026
- NPS — Bechler Backcountry Office (hours, permit pickup) — official · 2026
- Backpacker — Mr. Bubbles trip description (13.5 mi to 9D1, 110F pool) — community · 2019
- Jacob W. Frank trip report (Oct 2024, ~16 mi to pool) — community · 2024-10
Additional references for this record; a source link does not guarantee current conditions.
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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