Saddle Mountain, in central Washington near Mattawa, is one of the state’s best-known spots for petrified and agatized wood. The ridge runs for miles above the Columbia River, made up of layers of basalt and ash from ancient eruptions. Over time, wood that was buried in those flows was replaced with silica, leaving behind fossils that are now dug out by collectors.
The Collecting Experience
Reaching the dig sites isn’t always straightforward. The roads are rough and dusty, and higher-clearance vehicles do best. Once you’re there, it’s a matter of walking the hillsides and prying into the breaks in the basalt. Most collectors bring shovels, chisels, and pry bars to work material loose. It’s hot and dry country in the summer, so plenty of water and sun protection are musts.
What You’ll Find
The material at Saddle Mountain is usually limb casts and chunks of petrified or agatized wood. Some pieces are simple brown or gray, but others show agate interiors with subtle patterns. A few even take a polish well enough to cut into cabochons or display slabs. The best finds are full limb sections, still showing bark impressions or growth rings.
Why People Go
Even though the site is worked heavily, there’s still a steady trickle of material for those willing to dig. Part of the draw is simply the landscape itself—the views across the Columbia Basin from the top of the ridge are wide and impressive. For many rockhounds, Saddle Mountain is a rite of passage: a place where you can spend a day breaking rocks, come home dusty and tired, and hopefully have a few good pieces of agatized wood to show for it.
