Maston is a trail system North of Bend (technically part of the Redmond trail network) which provides a good mountain biking and trail running option in the winter months. Typically the soils here are too dry and sandy in the summer, but they hold up nicely in winter. Riding is fairly flat and there are a few moderately technical sections scattered throughout the system. The best part of the area is the Rockbar Trail which takes you through some carefully stacked lava rocks and along the edge of the canyon overlooking the Deschutes River. The rest of the trails have lots of interesting Juniper trees.
If you are looking for more elevation and some gnarly rocks – you can cross Cline Falls Highway and make your way up to Cline Butte.