The city of Lake Stevens has various facilities available for reservations: 

Lundeen Park and North Cove Park Shelter Reservations

Both Lundeen Park and North Cove Park offer swimming, a covered picnic area, playground, and wetland viewing areas. https://www.lakestevenswa.gov/303/Park-Shelter-Reservations 

North Cove and Davies Beach Boat Launches
The North Cove public boat launch is located at 12200 17th Place NE, one block south of City Hall. The Davies Beach boat launch is located at the intersection of N Davies Road and Chapel Hill Road. https://secure.rec1.com/WA/lake-stevens-wa/catalog/index

The Mill on Lake Stevens

The Mill on Lake Stevens (The Mill) is a multi-use building located at North Cove Park.  It is a versatile rental space with two levels, and is available for a variety of city, community, and private events, including home to the City Council Chambers.  https://www.lakestevenswa.gov/TheMill