This is the site where the first petrified tree was found in 1870.
Calistoga, California is home to the world’s largest petrified redwood trees, Sequoia langsdorfii, which are now extinct. This grove of magnificent trees was turned to stone in a volcanic eruption that occurred about 3.4 million years ago. Today, you can see the fossilized remains along a half mile paved trail (some uphill). If you add another half mile to your walk, you’ll also see an ancient 100 foot-high ash fall (looks like cement) and a view of Mt. Saint Helena seven miles away—the volcano was 
thought to have originated there. The trail is open for self-guided tours (interpretive signs are along the route), or take a one-hour docent led tour at no additional charge if you want to learn more and be able to ask questions. Poison oak grows in some areas along the trail, so take care not to touch it!
The fallen trees you see today are harder than steel, being mainly comprised of quartz, a very hard naturally occurring stone substance. Following the volcanic eruptions, the trees lay buried in the ash for millions of years. Time passed and the ground was saturated with water containing dissolved silicon and oxygen, or silica, from the overlying ash. One by one the molecules of silica replaced the molecules of the 
wood, turning the trees to solid stone. Some of the largest and most interesting trees and stumps have been given names such as “The Queen” (8 feet in diameter; 65 feet long) and “The Robert Louis Stevenson Tree.” Only 105 feet of the “Tunnel Tree” is exposed; it is said to be one of the best- preserved petrified trees in the world.
The Queen is 8 feet in diameter; 65 feet long.
William Travers first discovered this area in 1857, but it wasn’t until 1880 when writer Robert Louis Stevenson recounted his visit here in chapter two of his booklet, The Silverado Squatters, that the trees started to become famous. Most of the redwoods were excavated between 1910-1920. The Ollie Bockée family arrived in 1914 and further developed and advertised the area as a public attraction. Ollie’s heirs, the Hawthorne family, continue to improve the property. Designated a California Historical Landmark in 1978, the Petrified Forest presents a unique opportunity to see the preservation effects Mother Nature can create when conditions are just right.
IF YOU GO:
The Petrified Forest
4100 Petrified Forest Rd.
Calistoga, CA 94515
Phone: (707) 942-6667
Open every day at 10:00 a.m. Closes 7:00 pm in the summer (earlier in other seasons).
Adults $10; Kids 6-11 years $5
In addition to writing about her travels, Denise Seith is also a treasure hunter and loves a good latté. She and her husband own an online gold prospecting and metal detecting equipment store found at GoldRushTradingPost.com
I have been there grat place and a lot of History.