Sumas Mountain Regional Park is Abbotsford's best serious outdoor option, a 1,471-hectare park of forested slopes, mountain-bike routes, and hiking trails east of the city. The Chadsey Lake Trail is the usual target, with a small lake in the woods and links to longer routes.
The park makes Abbotsford feel less suburban. On a clear day, the higher viewpoints look across the eastern Fraser Valley toward Chilliwack and the surrounding mountains. Trails can be muddy and rough, so wear proper shoes rather than treating it like a city park.