An expansive cross country-oriented trail system.









FATMAP difficulty grade



Mountain biking in the Pacific Northwest is renowned for its gnarly freeride lines, massive dirt jumps, and steep downhill runs.

Compared to other parts of the Mountain West, it can sometimes be challenging to find good ‘ole fashioned cross country trails to ride.

Black Diamond Open Space fills this void in the Seattle Area. "BDOS offers lots of singletrack and variety, but is mostly based around XC,” according to [](

"There’s _[sic]_ a few freeride and downhill trails here and in the nearby Summit Ridge & Henry's Ridge, but by NW Washington standards, BDOS is pretty flat." This massive, complex trail system includes mile upon mile of interconnected non-motorized singletrack.

In total, there are at least 64 different named trails in this trail system, plus numerous connections to other nearby trail systems. You can easily construct a ride of any length and any difficulty in the Black Diamond Open Space—from a quick couple-mile jaunt in the woods, to this meandering 22-mile loop, or an even longer ride if you start connecting every single possible trail option that you pass.

If you’re looking for a respectable pedal, try out this recommend trail combination, and then continue adding or subtracting trails from here! Sources: