Complex sentence: Preserve Our Islands (POI) is a volunteer, non-profit organization committed to preserving all aspects of life and the environment on Vashon Island and Maury Island, and is opposed to Glacier Northwest's proposal to expand its gravel mine.
Split into simpler sentences: Preserve Our Islands (POI) is a volunteer, non-profit organization committed to preserving all aspects of life and the environment on Vashon Island and Maury Island. It is opposed to Glacier Northwest's proposal to expand its gravel mine.