Just about an hour outside Beverly Dunes is the second dune site in Washington where ATVer can have a great time. This is an area of 3,000 acres, 2,000 acres of which is open to all OHV.
Moses Lake Dunes has somewhat similar sand to the dunes in Beverly, but it is finer due to ash fall from the Mt St Helene's eruption in the '80s. This makes the sand dustier, so expect to come home with sand in your "nooks and crannies." Because the wind has an eastward flow the dunes flow this way also. Be aware of their lay before starting out on a run, there are 20-foot drops in areas. Also, be aware of any rules and regulations of the area before starting. The Moses Lake Sheriff Department can clue you in on any updates or changes. As with Beverly Dunes, there is a rule that says all ATVs/OHVs need to have a flag on their antenna for visibility. Take care watching for any other ATVer in your riding area; blowing sand does mess with visibility.
Besides all the variety of ATV experiences here, the gem of surprise is the Moses Lake itself. You might want to double your daytrip time and take your ATV and Jet Ski along. No Jet Ski, no problem, just spend some time swimming. There is boating allowed, too. This is a nice place for the water nuts in the family. Those who want to ATV can spend the weekend on the dunes; those who love the water can spend the weekend on the lake. The perfect ATV combination, you can swim off the sand every evening.