The Napa Valley is renowned for its terroir – and grapes aren’t the only thing to benefit from the rich soil hereabouts. At the north end of the Valley, the high volcanic ash content has generated another local specialty: therapeutic and rejuvenating mud baths.

The native Wappo Indians invented the concept, mixing the local ashy soil with warm, mineral waters that bubbled up in natural springs. Soon after the Gold Rush, entrepreneur Sam Brannan commercialized the idea, creating a fashionable health resort that would be “the Saratoga of California.” And in 1946, a young chiropractor named John “Doc” Wilkinson founded Calistoga’s first twentieth-century spa, using a mixture of volcanic ash, hot spring water, natural minerals, and peat moss and offering other treatments like massage and body wraps.

Today the town is filled with mud-based spas and therapies, which range from the functional and funky to the luxurious. Aromatherapies and other amenities are often added to the treatments. Whichever you choose, it’s a “must try” for any Napa Valley stay, especially after a hard weekend of wine-tasting and culinary indulgence.

Here are some local favorites. Note that all venues listed are in Calistoga. Most facilities also feature warm water mineral pools and a full menu of spa services.

• Golden Haven Hot Springs – offers room and spa packages, couples mud baths, and girlfriends specials. 1713 Lake Street; 707-942-8000.
• Dr. Wilkinsons is considered the granddaddy of the mud bath resorts while maintaining traditional services with contemporary lodging and pools. 1507 Lincoln Ave, 707-942-4102.
• Mount View Hotel & Spa offers its signature mud bath, in which a rich natural mud is added to a deep warm whirlpool tub. 1457 Lincoln Avenue; 707-942-6877.
• Indian Springs features several pools in which to “take the waters” of its own thermal geysers. 1712 Lincoln Avenue; 707-709-8139.
• Calistoga Spa Hot Springs is one of only a few Calistoga spas that uses locally harvested volcanic ash mud. 1006 Washington Street; 707-942-6269.
• Baths at Roman Spa also offers couples’ experiences in its traditional mud baths. 1300 Washington Street; 707-942-2122 or 800-404-4772.
• Solage Calistoga features the “Mudslide,” a three-part experience that includes The Mud, The Waters, and The Rest. The Mudslide can be enjoyed in private, as a group, or as a couples’ shared experience. 755 Silverado Trail; 855-942-7442.