From the Park District:

A 43.0 acre park developed as an equestrian park that has become a multi-use and large event center. It is located in the center of Vashon Island off Southwest 220th Street. Portions of the former NIKE missile site conserve stands of second growth woodlands. A Foster cross-country equestrian jumping course has been cleared around the perimeter of the site and is also used for hiking, cross-country track competition and practice, horseback, and mountain bike riding. Groups associated with events use various areas within the park to camp during the event.
The south central portion of the property has been developed into an equestrian center with training and showing rings, 2 judge’s booths, arenas, and outdoor stalls.

Address: SW 220th Street between 111th SW and Old Mill Road on the east and west, Vashon, WA