The Leavenworth Skateboard Park (6,000 square feet) is located at the East end of town by the Cascade High School. As you drive East on Highway 2 turn left on Chumstick Highway. It is across the street from the Leavenworth fire department.
Here are directions from Google Maps.
Leavenworth Skatepark by Northwestskater
Skateboarding is inherently risky, please be aware of landowners limitation of liability to recreational users: Washington Laws, 1997 Chapter 26 [Substitute Senate Bill 5254]: An Act limiting liability of landowners for injuries to recreational users [RCW 4.24.210]