The Mountains to Sound Greenway stretches over 100 miles along Interstate 90 from the shores of Puget Sound in Seattle, over Snoqualmie Pass and into Central Washington. Much of the Greenway is public land and includes over 750,000 acres held by local, state and federal agencies in trust for the public good. The Greenway encompasses protected and working forests, farms, historic towns, lakes, campgrounds, rivers, trails and wildlife habitat just outside the Seattle metropolitan area.

The Mountains to Sound Greenway provides natural areas and breathing room for a growing population. Open space conservation on this scale is an award-winning answer to the challenge of balancing human development with a healthy natural environment.

The Mountains to Sound Greenway Trust is a 501(c)3 nonprofit organization based in Seattle, and it has received numerous awards including National Scenic Byway designation, a Vision 2020 Award from the Puget Sound Regional Council, the Cascade Land Conservancy Conservation Award, Scenic America Stafford Award, a Conservation award from National Scenic Byways for the Re-Greening of Zorro Mountain, an American Society of Landscape Architects Merit Award, a Washington State Parks Volunteer Award and the White House Millennium Trail Award.