Thing to Do

Visit Sulphur Works in Winter

A woman on showshoes takes a photo of a large mudpot in a mountain landscape.
Enjoy the sights, sounds, and scents of Sulphur Works.

The boiling mudpots and hissing steam vents at Sulphur Works hydrothermal area are accessible year-round via a two-mile round-trip, over-snow route. Hydrothermal features are visible on both sides of the snow-covered park highway route and heat from these features often keeps the portion of road between them clear of snow. This is the only park hydrothermal area that is accessible in the winter months (approximately November through April). The 30-mile park highway closes to through traffic in the snow season (approximately November through April). 

Get There

Distance: 2 miles round-trip
Elevation: 6,700 to 7,000 feet
Average Snowshoeing Time: 1 hour

To access Sulphur Works, follow the snow-covered park highway route from the Southwest Area parking area. The route passes the Kohm Yah-mah-nee Visitor Center and a sledding area. The one-mile route climbs gently along a hillside above Sulphur Creek and offers a partial view of Lassen Peak at about the halfway point. The left side of the route is bordered by steep side hills. Be aware of avalanche danger by watching for movement on the steep slopes above. Near the end of the route you will cross Sulphur Works bridge and the summertime Sulphur Works parking area on your left. Rising steam and the scent of rotting eggs makes your destination is unmistakable. From here you can return the way you came, continue 1/2 mile up the highway route to Windy Point, or begin the steep climb to Ridge Lakes. View these and other winter routes in the Southwest Area.

Oversnow Travel

In the winter months, travel by snowshoe or cross-country ski is best for traveling over the deep snowpack. Bring your own equipment; rentals are not available in the park. This popular route may be hardpacked, especially through the sledding area just beyond the visitor center. This route is recommended for advanced cross-country skiers only as footprints and snowshoe tracks on this popular route freeze and make skiing more difficult. The Manzanita Lake Area offers better routes for beginners. We do not recommend walking without snowshoes unless the route is completely hardpacked. Otherwise, you should be prepared for your feet and legs to break through the snow frequently in an exhausting experience known as post-holing. Learn about  why not creating postholes is good for everyone from Leave No Trace Center for Outdoor Ethics.

Winter Etiquette

Improve everyone's safety and enjoyment by adhering to the following winter etiquette recommendations:

  • Do not walk on ski tracks. Footprints and snowshoe tracks create hazards that make skiing more difficult.
  • Snowshoe parallel to the ski track. Using a separate track ensures snowshoers remain clear of downhill skiers.
  • Yield to faster skiers or downhill traffic. Step to the side to allow skiers traveling downhill to safely pass. In all other cases, yield to those traveling uphill, as they are working harder and have the right of way.
The two-mile round-trip route takes about one hour on snowshoes. 
In the winter months, Sulphur Works is accessible by snowshoe or cross-country ski (advanced skiers only) via the snow-covered park highway route.
Pets are not permitted on snow-covered routes. 
Entrance fees may apply, see Fees & Passes information.
Sulphur Works hydrothermal area is locate on Lassen Volcanic National Park Highway, one mile north of the Kohm Yah-mah-nee Visitor Center. The area is accessible only via over-snow travel in the winter months (approximately November through April). 
Winter, Spring
Time of Day
Accessibility Information
In the winter and spring snow seasons, Sulphur Works is only accessible via over-snow travel. All non-motorized modes of transportation are permitted on the snow-covered highway route. The route gradually climbs 300 feet in one mile.

Lassen Volcanic National Park

Last updated: December 29, 2020