Reservations at Mason Lake are EXCLUSIVELY for the enjoyment of Green Diamond, and Simpson employees. and other qualified members, NOT OPEN TO PUBLIC.
If you are a non member local business looking to rent one of our facilities please contact our office at 360-426-0737.


Only Credit Card Payments Will Be Accepted at the Park



Secure on-line reservations provided by Leisure Interactive.
Once you complete your on-line reservation you will receive a reservation confirmation email.
Please contact the Mason Lake Recreation Area directly at (360)426-0737 if you have any questions or changes to your reservation.
Office Hours are 8:00 am to 5:00 pm Mon - Sun.

Click Here to View or Print the Mason Lake Recreation Area Rules and Regulations

Park closing for day-use and camping October 1st - April 30th. Loud Music is not allowed in picnic shelters.