The geological history of our state has encompassed many great changes,
one of them being the many lava flows from volcanic fissures. Centuries
ago, the interior of Washington was swampy and mild with many trees such
as cypress, oak, elm and gingko growing in wet areas. Layers of logs were
preserved with each new lava flow, and as the layers grew deeper, many of
the logs became waterlogged and lay protected in deep water. Over time,
water continued to seep through the lava and permeate the wood with
silica. Eventually, the wood fiber was completely replaced by silica thus
petrifying many logs. The petrified wood is perfect in form and detail to
the original wood. In 1975, petrified wood was adopted as the state gem.
The best place to see petrified wood is the Gingko Petrified Forest State
Park in Vantage.