- The Cretaceous–Paleogene (K–Pg) extinction event, also known as the Cretaceous–Tertiary (K–T) extinction, was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than 25 kilograms (55 pounds) also became extinct, with the exception of some ectothermic species such as sea turtles and crocodilians. It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the Cenozoic era, which continues to this day.
- Rockhounding Saddle Mountain Washington For Petrified Wood (rockseeker.com)
Saddle Mountain, a remote and rocky ridge located in central Washington. These hills rise to 2700 feet and offer stunning views of the desert landscape and the Columbia River below. But that’s not all – the fossilized wood on these rugged hills contains a record of the area’s geological history. Petrified or opalized wood is the official gemstone of Washington, and Saddle Mountain is a treasure trove for rock enthusiasts who love agatized wood.