Roslyn is a city in Kittitas County, Washington, United States. The population was 893 at the 2010 census. Roslyn in located in the Cascade Mountains, about 80 miles east of Seattle.The town was founded in 1886 as a coal mining company town. During the 20th century, the town gradually transitioned away from coal, and today its economy is primarily based on forestry and tourism. The town was the filming location for The Runner Stumbles, Northern Exposure, and The Man in the High Castle. Much of the town's history is preserved, and its downtown was added to the National Register of Historic Places in 1978.