- Cottonwood Island Wildlife Area Unit (wdfw.wa.gov)
The Cottonwood Island Unit is a unique forested property that is representative of a historic habitat type that would have been more widespread along the lower Skagit River Valley. It provides valuable mature cottonwood forest habitat for a variety of forest birds and raptors, primarily buteos and eagles. The remnant of Cottonwood Slough also provides off-channel habitat for salmonids during certain times of the year and has been evaluated for potential habitat restoration projects.
- Opal (Wikipedia)
Opal is a hydrated amorphous form of silica (SiO2·nH2O); its water content may range from 3% to 21% by weight, but is usually between 6% and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms of silica, which are considered minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt.