Late-season note (checked October 22, 2026): The Park Service lists Bumpass Hell as open for hiking. It opened for the 2026 season on June 26. But this is the end of the season. At 8,200+ feet, the first heavy snow can close the trail any day, and the park highway usually closes for winter around November. Check the park’s current conditions or call 530-595-6100 before you drive up.
Picture this: you walk along a mountain trail with views of old volcanic peaks, round a corner, and look down into a valley that’s steaming. White clouds hiss out of the ground, milky blue pools bubble, mud pots gurgle, and the rocks are stained yellow, orange, and white. That’s Bumpass Hell, and the Bumpass Hell Trail is the most popular hike in Lassen Volcanic National Park.
It’s a short hike, about 3 miles round trip, but it comes with a few catches. Snow can keep it closed until July, the parking lot fills by mid-morning, and the last stretch drops steeply into the basin, which means a steep climb back out.
This guide covers everything you need: whether it’s open, distance and difficulty, the trail step by step, what you’ll see, safety, parking, fees, the best time to go, kids, and other hikes nearby.
Cover photo: The boardwalk through the Bumpass Hell basin. Photo: Royce Fonseca / Unsplash
Bumpass Hell Trail: Quick Facts
| Detail | Information |
|---|---|
| Location | Lassen Volcanic National Park, Northern California |
| Trailhead | Off the park highway, about 7 miles from the Southwest Entrance |
| Distance | About 3 miles round trip |
| Elevation | 8,200 to 8,400 feet |
| Elevation change | Gentle climb, then about 300 feet down into the basin |
| Time needed | About 90 minutes to 2 hours |
| Difficulty | Easy to moderate (steep last section) |
| Trail type | Out and back |
| Main attraction | The park’s largest hydrothermal area (16 acres) |
| Season | Usually July to October; 2026 opening was June 26 |
| Toilets | Vault toilets at the trailhead only |
| Dogs | Not allowed, even in carriers |
| Reservation | Not needed |
| Entrance fee | $30 per vehicle (April 16–November 30), cards only |
You may see 2.8 miles on the park’s trail-conditions page and 3 miles on its hiking page. Plan for about 3 miles, plus time to wander the boardwalk.
Is Bumpass Hell Trail Open Now?
As of October 22, 2026, the Park Service lists the trail as open (“Hike”). The trail opened for the season on June 26, 2026, one of its earliest openings in years thanks to a light snow year.
Keep in mind:
- Late October is the end of the season. Fresh snow and ice can close the trail without much warning.
- The park highway closes for winter, usually from about November until June, at the Kohm Yah-mah-nee Visitor Center in the south and Loomis Plaza in the north. Once it closes, you can’t drive to the trailhead.
- Always check before you go. Look at the park’s current conditions page or call the park at 530-595-6100.
When does Bumpass Hell open each year?
It depends on how much snow fell over the winter. Here are recent opening dates from the Park Service:
| Year | Opening date | April 1 snow depth at Lake Helen |
|---|---|---|
| 2020 | July 2 | 10 feet |
| 2021 | June 16 | 9.5 feet |
| 2022 | July 1 | 8 feet |
| 2023 | August 4 | 18 feet |
| 2024 | July 21 | 16.1 feet |
| 2025 | July 21 | 17.3 feet |
| 2026 | June 26 | 7.5 feet |
The pattern: Big snow years mean a late opening, sometimes not until August. In an average year, plan on mid-July.
Where Is Bumpass Hell?
Bumpass Hell is in the southwest part of Lassen Volcanic National Park, in Northern California between Redding and Lake Almanor. The trailhead is a parking area right on the Lassen Volcanic National Park Highway (part of Highway 89), about 7 miles north of the Southwest Entrance and the Kohm Yah-mah-nee Visitor Center.
The trail starts at about 8,200 feet. That’s high enough that you may feel short of breath, even on the easy first mile.
Fill up first: Gas stations near the park are limited. Coming from the south, fill up in Red Bluff or Chester.
Bumpass Hell Trail Step by Step
1. Start at the trailhead
The trail begins at the Bumpass Hell parking area. Use the vault toilets here. There are none on the trail or in the basin.
2. Walk the easy first mile
The first mile is wide (about 4 feet), with packed gravel and dirt and only a gentle climb. It follows the side of Bumpass Mountain with big, open views across the valley. There’s very little shade, so wear a hat.
3. Stop at the Brokeoff Volcano overlook (0.5 mile)
About half a mile in, an overlook shows you the five remnant peaks of ancient Brokeoff Volcano (also called Mount Tehama). This giant volcano collapsed and wore away long ago, and these peaks are what’s left of its rim.
4. Look down into the basin (1 mile)
At about the 1-mile mark, you reach an overlook above Bumpass Hell. From here, you can see steam drifting across a pale, colorful bowl and smell the sulfur, a “rotten egg” smell.
5. Descend into the basin
Now the trail gets steeper. It drops about 300 feet on a narrower path with rock steps and loose gravel. Take it slowly, and use trekking poles if you have them. This is the part people talk about, because you have to climb back up it on the way out.
6. Explore the boardwalk
At the bottom, a boardwalk winds through the basin, taking you close to the action safely. You’ll see:
- Fumaroles, vents that hiss out steam and volcanic gas
- Boiling pools of milky blue and gray water
- Mud pots, bubbling pools of thick, gray mud
- Ground stained yellow, orange, and white by minerals
A second trail leads to another overlook on the east side of the basin.
Big Boiler, one of the vents here, is among the hottest fumaroles in the world. Its steam has been measured at around 322°F (161°C).
7. Climb back out
Return the same way. The climb out of the basin is the hardest part of the hike, so pace yourself, then enjoy the easy last mile back to the car.
Why Is It Called Bumpass Hell?
The basin is named after Kendall Vanhook Bumpass, a cowboy and early guide in the area in the 1860s. As the story goes, he hoped to make money from the steaming basin, but while exploring it he broke through the thin crust and badly burned his leg, which later had to be amputated.
His painful mistake is the best safety lesson in the park: the ground here can look solid and still be a thin shell over boiling, acidic water.
What Makes Bumpass Hell Special?
Bumpass Hell is the largest hydrothermal area in Lassen Volcanic National Park, covering about 16 acres. Lassen is one of the few places in the world where you can see all four main types of volcanoes, and Bumpass Hell is where you can see the heat underneath it all.
Here’s how it works: rain and snowmelt seep deep underground, where they’re heated by hot rock from the volcanic system. The hot water and gases rise back to the surface, creating the steam vents, boiling pools, and mud pots you see from the boardwalk. Acidic water breaks down the rock into clay, which is why the ground is so pale and soft.
How Hard Is Bumpass Hell Trail?
The Park Service rates it easy to moderate. Most people with basic fitness can do it, but it isn’t a flat stroll.
| Section | Difficulty | What to expect |
|---|---|---|
| First mile | Easy | Wide, gentle trail with views |
| Descent into the basin | Moderate | Narrow, steeper path with rock steps |
| Boardwalk | Easy | Flat walking, lots of stops |
| Climb out | Moderate | About 300 feet back up at high elevation |
What makes it harder:
- The altitude. At 8,200+ feet, you’ll breathe harder than usual.
- The climb back out. It’s short but steep.
- Sun and wind. There’s little shade, and the trail can be cold and windy even in summer.
- Snow patches. Early and late in the season, shaded spots can stay icy.
The Park Service notes that knee and ankle injuries are the most common injuries in the park, so wear sturdy shoes and watch your step.
Good for beginners? Yes. Go slowly and plan on about 2 hours. See our hiking for beginners guide for more tips.
Can Kids Hike Bumpass Hell?
Yes, with close supervision. The Park Service says kids age 5 and up can often finish the first mile, but they may need help on the steep section into and out of the basin.
The bigger concern is the hydrothermal area itself. Keep kids right next to you on the boardwalk, explain the dangers before you go in, and never let them step off the boardwalk or touch the water. Strollers won’t work past the first mile.
Safety Tips
The basin is beautiful, but it can be dangerous.
- Stay on the trail and boardwalk. Ground that looks solid can be a thin crust over boiling, acidic water or mud. Leaving the trail in hydrothermal areas is dangerous and against park rules.
- Never touch the water or mud. It’s acidic and can hurt your skin even if it doesn’t feel hot.
- Wear closed-toe shoes with good grip and ankle support.
- Bring water and sun protection. There’s very little shade.
- Pack a warm layer. It’s often cold and windy at this elevation.
- Turn back if snow or ice covers the steep sections.
These rules matter. The Park Service has reported visitors badly burned after leaving trails at other hydrothermal areas in the park, including Devils Kitchen in 2010 and Sulphur Works in 2012.
Best Time to Hike Bumpass Hell
| Month | Typical conditions | Our take |
|---|---|---|
| May–June | Snow, trail usually closed | Don’t count on it |
| July | Trail usually opens as snow melts | Check the opening news |
| August | Snow-free, warm days | One of the best times |
| September | Cooler, fewer crowds | One of the best times |
| October | Cold mornings, first snow possible | Check conditions first |
| November–April | Highway closed, deep snow | Not a hiking trail in winter |
Best months: August and September.
Best time of day: Early morning. It’s quieter, you’ll beat the parking rush, and the steam shows up best in cool morning air. Late afternoon and weekdays are also less crowded.
Parking at Bumpass Hell
The trailhead lot is right on the park highway, but it’s limited and often full from mid-morning to early afternoon, especially on weekends.
- Arrive before 9 a.m. or come in the late afternoon.
- Don’t park on the shoulder or on plants.
- If it’s full, visit Sulphur Works or Lake Helen first, then try again later.
Fees and Permits
- Trail permit: Not needed. No reservations either.
- Entrance fee (April 16–November 30): $30 per vehicle, $25 per motorcycle, or $15 per person on foot or bike, valid for 7 days.
- Entrance fee (December 1–April 15): $10.
- Payment: Cards only. The park is cashless.
- Annual pass: $55, which also covers Crater Lake, Whiskeytown, and Lava Beds. Planning a road trip? See our Garfield Peak hike at Crater Lake guide.
What to Bring
| Item | Why |
|---|---|
| Hiking shoes with good grip | Rock steps and loose gravel on the descent |
| Water | High elevation and little shade |
| Sun hat, sunglasses, sunscreen | The trail is exposed |
| Warm, windproof jacket | It’s often cold and windy, even in summer |
| Trekking poles | For the steep climb into and out of the basin |
| Snacks | Especially for kids |
| Camera | The colors are amazing |
| Offline map | Cell service is limited in the park |
Need a good layer? See our guide to the best waterproof hiking jackets.
Bumpass Hell vs. Sulphur Works
If Bumpass Hell is closed, or you’d rather skip the hike, Sulphur Works is the easy alternative.
| Feature | Bumpass Hell | Sulphur Works |
|---|---|---|
| Walk | About 3 miles round trip | A few steps from the road |
| Effort | Easy to moderate | Very easy |
| Size | Largest hydrothermal area in the park | Small roadside area |
| Highlights | Boardwalk, boiling pools, big fumaroles | Bubbling mud pots and steam vents |
| Season | Usually July–October | Whenever that stretch of park highway is open |
Sulphur Works sits right along the park highway, about a mile from the Southwest Entrance. It’s perfect for families, people with limited mobility, or a quick stop on the way in.
Other Hikes Near Bumpass Hell
Lassen Peak
The big one. The trail climbs about 2,000 feet in 2.5 miles to the top of Lassen Peak (10,457 feet), a volcano that last erupted from 1914 to 1917. It’s about 5 miles round trip and strenuous, with huge views. The trailhead is next to Lake Helen, just up the road from Bumpass Hell.
Kings Creek Falls
A forest and meadow walk to a cascading waterfall, about 2.5 to 3 miles round trip. It’s a nice change from the volcanic landscape.
Boiling Springs Lake
About 3 miles round trip to a steaming, pale green lake in the Warner Valley area, on the park’s remote south side. It’s a separate drive from Bumpass Hell.
Sulphur Works
A quick roadside stop to see bubbling mud pots (see above).
Sample Day in Lassen Volcanic
| Time | Plan |
|---|---|
| 8:00 a.m. | Arrive at Bumpass Hell trailhead |
| 8:15–10:15 a.m. | Hike to the basin, explore the boardwalk, hike back |
| 10:30 a.m. | Stop at Lake Helen for photos |
| 12:00 p.m. | Picnic lunch |
| 1:30 p.m. | Visit Sulphur Works |
| Afternoon | Drive the park highway and stop at viewpoints |
Strong hikers can swap the afternoon for Lassen Peak. Just start early, since afternoon storms can roll in.
Is Bumpass Hell Worth It?
Absolutely. Few short hikes anywhere give you this much: mountain views, an ancient volcano, and a steaming, bubbling basin you can walk right into on a boardwalk. If you’ve never seen mud pots and steam vents up close, it’s unforgettable.
Just plan around the short season, get there early for parking, and stay on the boardwalk.
Bumpass Hell Trail FAQs
Is Bumpass Hell Trail open now?
As of October 22, 2026, the Park Service lists it as open. It’s late in the season, though, so snow could close it any day. Check the park’s current conditions before you go.
How long is the Bumpass Hell Trail?
About 3 miles round trip. Some park pages list 2.8 miles.
How long does it take to hike Bumpass Hell?
About 90 minutes to 2 hours, including time on the boardwalk.
How hard is the Bumpass Hell Trail?
Easy to moderate. The first mile is gentle. The steep 300-foot drop into the basin, and the climb back out, are the hardest parts.
When does Bumpass Hell open?
Usually in July, depending on snow. In 2026, it opened on June 26. In big snow years, it may not open until August.
Can you hike Bumpass Hell in winter?
No. The trail is buried in snow, and the park highway is closed from about November to June.
Is Bumpass Hell safe for kids?
Yes, with close supervision. Kids must stay on the boardwalk at all times and never touch the water.
Are dogs allowed at Bumpass Hell?
No. Pets aren’t allowed on park trails, even in carriers. Service animals are allowed.
Do you need a permit for Bumpass Hell?
No permit or reservation is needed. You just need a park entrance pass.
Is there parking at Bumpass Hell?
Yes, but it’s limited and often full from mid-morning to early afternoon. Arrive early.
Are there bathrooms on the trail?
Only vault toilets at the trailhead. There are none on the trail or in the basin.
What does Bumpass Hell smell like?
Rotten eggs. That’s hydrogen sulfide gas coming from the vents.
Why is it called Bumpass Hell?
It’s named after Kendall Bumpass, an early guide who broke through the crust in the 1860s and badly burned his leg.
Final Thoughts
The Bumpass Hell Trail is one of the most unusual hikes in California. In about 3 miles, you go from mountain views to a steaming, bubbling, rainbow-colored basin that feels like another planet.
Go between July and early October, check that the trail is open, get there early, and stay on the boardwalk. Do that, and it’ll likely be the highlight of your trip to Lassen.