Welcome to the Mountains to Sound Greenway National Heritage Area

The Mountains to Sound Greenway National Heritage Area is a unique geographic corridor made up of connected ecosystems and communities spanning 1.5 million acres from Seattle to Ellensburg along Interstate-90 in Washington state. The Mountains to Sound Greenway Trust is a coalition-based organization that leads and inspires action to conserve and enhance this special landscape, ensuring a long-term balance between people and nature.