199°F6,932 ftOpenRoadsideNational Park ServiceCamping nearby (5.8 mi)
Very Hot Source — Use Extreme Caution
At 199°F, the source water at Sulphur Works, Tophet Hot Springs is hot enough to cause burns. Some hot springs this hot have cooler side pools or downstream areas suitable for soaking — always test the water temperature before entering.
Image via Wikidata
Sulphur Works and Tophet Hot Springs emerge at a dramatic 199°F at 6,932 feet elevation within Lassen Volcanic National Park, one of California's most spectacular geothermal displays accessible directly from the main park road.
The springs produce intense geothermal activity visible from the roadside, with sulfurous steam rising from colorful mineral deposits in an alpine volcanic landscape shaped by recent geological upheaval and subject to winter snowfall exceeding 200 inches.
History of Sulphur Works, Tophet Hot Springs
These springs lie in Lassen Volcanic National Park, which protects one of the world's most active geothermal zones. The springs' mineral chemistry and water temperatures reflect recent magmatic activity beneath the peak.
Roadside access from Lassen Peak Highway makes viewing accessible to all visitors. Winter closures occur due to heavy snowfall. Manzanita Lake Campground within the park sits 9.4 kilometers away and offers full facilities.
Is Sulphur Works, Tophet Hot Springs worth visiting?
Best for
Observing powerful hot springs
Easy day trips
Overnight camping trips
Not ideal for
Casual soaking
Sulphur Works, Tophet Hot Springs is well suited for observing powerful hot springs and easy day trips.
Monthly Climate
29°Jan
29°Feb
32°Mar
37°Apr
45°May
56°Jun
65°Jul
64°Aug
57°Sep
46°Oct
35°Nov
28°Dec
Annual Precip: 45.7 inAnnual Snow: 208.9 in
Best Time to Visit
DecemberAir 28°F · Water 199°F · +171° contrast
JanuaryAir 29°F · Water 199°F · +170° contrast
FebruaryAir 29°F · Water 199°F · +170° contrast
December offers 36°F more contrast than August
USGS Field Measurements
Recent Temperature
39.2°F
(4.0°C)Measured Jun 30, 1981
Water ChemistrySampled 1981-06-30
The water at Sulphur Works, Tophet Hot Springs is slightly acidic (pH 6.1) with 88 mg/L total dissolved solids.
Overview
Manzanita Lake Group Campground is located at the west end of Loop B in Manzanita Lake Campground, the largest campground in Lassen Volcanic National Park. It is within walking distance of scenic Manzanita Lake, a popular fishing and family destination, and offers impressive views of Lassen Peak, the largest volcano in the park at 10,457 feet.Recreation
Manzanita Lake is popular with fly fishermen who enjoy the catch-and-release policy. Non-motorized boating is also permitted and kay...
What is the water temperature at Sulphur Works, Tophet Hot Springs?
Sulphur Works, Tophet Hot Springs has a water temperature of 199°F (93°C). This is considered a hot spring, well above body temperature.
Where is Sulphur Works, Tophet Hot Springs located?
Sulphur Works, Tophet Hot Springs is located in Plumas County, California at 6,932 feet elevation, near Chester. Coordinates: 40.4470°N, 121.5360°W.
How do I get to Sulphur Works, Tophet Hot Springs?
Sulphur Works, Tophet Hot Springs has Roadside road access, with the nearest road being Lassen Peak Highway (180 ft from the road).
Is Sulphur Works, Tophet Hot Springs free to visit?
Sulphur Works, Tophet Hot Springs has Open access. It is managed by National Park Service.
Can I camp near Sulphur Works, Tophet Hot Springs?
Yes, Manzanita Lake Group Campground is located nearby (5.8 miles away).
What minerals are in the water at Sulphur Works, Tophet Hot Springs?
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 6.1 (slightly acidic). Total dissolved solids measure 88 mg/L.
Is it safe to soak at Sulphur Works, Tophet Hot Springs?
The water at Sulphur Works, Tophet Hot Springs reaches 199°F, which can cause severe burns. Do not enter the source pool directly — look for cooled side pools or downstream areas where the water has cooled to a safe temperature. Always tell someone your plans before visiting remote hot springs.
Is Sulphur Works, Tophet Hot Springs crowded?
Sulphur Works, Tophet Hot Springs is accessible from a paved road, making it easy to reach. Weekends and holidays may be busier — consider visiting on a weekday for a quieter experience.
What should I bring to Sulphur Works, Tophet Hot Springs?
Essentials for Sulphur Works, Tophet Hot Springs: swimsuit, towel, water bottle, warm layers for before and after soaking, camping gear, a trash bag to pack out what you pack in. The water is over 110°F — test the temperature before entering and watch for scalding near the source.
