Petrified wood, a geological wonder, offers a tangible link to ancient forests transformed into stone over millions of years. This material forms when organic wood is buried rapidly, often by volcanic ash or sediments, in an oxygen-deprived environment. Over time, mineral-rich groundwater permeates the wood, replacing the organic material with minerals like silica while preserving the original cellular structure. Oregon, with its complex geological history marked by extensive volcanic activity, is a notable region where these fossilized remnants can be found.
Prime Locations for Petrified Wood
Oregon’s diverse landscapes, particularly its high deserts and areas influenced by ancient volcanic activity, provide prime opportunities for discovering petrified wood. Much of the petrified wood in Oregon dates back tens of millions of years, often from the Miocene epoch (23 to 5 million years ago), a period characterized by significant volcanic eruptions that buried forests under ash and sediment.
Vast stretches of public lands managed by the Bureau of Land Management (BLM) and some National Forests in Eastern and Central Oregon are known for petrified wood deposits. Eastern Oregon is a particularly rich source, with specific areas like Bear Creek Rockhounding Area recognized for abundance. Hampton Butte is another popular location, noted for its unique green petrified wood near Brothers. Central Oregon features sites like Dendrite Butte and Congleton Hollow, yielding opalized petrified wood and limb casts. These areas often contain fossilized wood on gravel bars, lake shorelines, and in fields, where erosion has exposed the material.
Rules and Responsible Collection
Collecting petrified wood on public lands in Oregon is subject to specific regulations. On lands managed by the Bureau of Land Management (BLM) in Oregon and Washington, individuals can collect petrified wood for personal, non-commercial use without a permit. The daily limit is 25 pounds, plus one additional piece, with an annual maximum of 250 pounds per person. Pooling quotas among multiple individuals to collect a single piece exceeding 250 pounds is prohibited, and any amount over these limits requires a permit.
For lands managed by the U.S. Forest Service, the general limit for collecting specimens is around 10 pounds. Collectors are advised to adhere to BLM guidelines for personal, non-commercial use. Regardless of the managing agency, the use of motorized equipment, heavy machinery, or explosives for collection is prohibited; only hand tools like shovels, picks, and hammers are allowed. Always obtain permission from landowners before collecting on private land. Collection is restricted in developed recreation sites, wilderness areas (where only surface collection may be allowed), and cultural or historic sites.
Identifying and Collecting Tips
Identifying petrified wood involves looking for specific characteristics. Petrified wood often retains the texture, grain patterns, and growth rings of the original tree, but it will feel dense and stone-like. The colors can vary widely, from browns, grays, and blacks to vibrant reds, oranges, greens, and blues, depending on the mineral impurities present during the petrification process. For example, iron oxides can produce red, yellow, and brown hues, while manganese can result in pink or orange colors.
When searching for petrified wood, focus on known areas like dry washes, hillsides, and gravel bars in riverbeds, where erosion may have exposed pieces. Keep an eye out for smooth, often curvy sections that might resemble bark. Basic tools for collecting include a rock hammer, sturdy shoes for navigating uneven terrain, and a backpack for carrying finds. Always carry water, inform someone of your whereabouts, and be aware of weather conditions and potential hazards.