If you have entered Lassen Park through the main entrance in the south, Sulphur Works is the first geothermal area on your way. Probably it marks the spot, which had been occcupied by the 3,350 m (11,000 feet) high peak of the stratovolcano Mount Tehama 600,000 - 400,000 years ago. Since Sulphur Works is traversed by the parks main road, hiking distances are really short. From 1865 up until 1952 it was privately owned and in the early times used for sulfur mining. Later on the owners built up extensive touristic infrastructure, comprising mineral baths, a restaurant and shops. The area has been subjected to natural changes in the geothermal features frequently. Some of them were quite dramatical, such as the formation of the large mud pot next to the roadway in 1936. This boiling mud pot is the main attraction still today, even if it dries out in autumn.
On the both sides of the road slopes of weathered andesite rock display the bright colors of sulfur and sulfur minerals.