I took my neighbor boy to Mar Don 5 or 6 years ago during Memorial Day and we had a good time. The staff at the store shared some great tips on where and how to bait fish for warm water species in the seeps lakes below the dam. We caught a stringer of small pumkinseed on what I think were maggots that we purchased at the store under the bobber and hooks they recommended.
The Mar Dawn campground was crowded, not much room between campsites but our neighbors had kids, were friendly and even shared pleasant time around the fire at night.
We have found that any place in central wa that is a campground on a lake allowing bait fishing and jet skis can tend to have drunk, loud white trash but gosh darnnit if you are friendly and interested in the white trash the majority of them are friendly back.
Last year I took my 8 yr old son and 11 yr old neighbor boy to Blue Lake campground for memorial day. We had a blast. The campground staff and store was great. The trout fishing was good (due to buying bait and following directions of the camp store lady) and our neighbors were profane but friendly. One night while cleaning our fish I let the boys sit at the campfire. I came back 1 hr later. Our neighbors took pity on my boys. The neighbors brought some fuel from their camp and built the fire into an inferno that lit up our entire camp. The look on my boys faces was memorable. Each night they looked onto our neighbors fire with envy, but this night they had a great ******* fire. Needless to say, we have booked the same spot Memorial day and are looking forward to the camping, fishing and campfires. Blue Lake resort has campsites that are right on the lake. We were able to beach to tie up our drift boat just outside our tent.
I'd say take your kid, if the neighbors are obnoxious (most will neighbors will not be), just take your child out into the numerous areas around Potholes to get away from the crowd.
Do something physical like hiking or canoeing to wear them out, then return to camp just before bed time. The kids will sleep and never hear a word from the drunks. Your kids will love you for taking them out into the dessert.
If you go later in the season, The City of Moses Lake has a great water park that is very reasonable in cost. I took my 2 neighbor boys plus my son to Potholes State Park one year for memorial day weekend. It was unbearably hot - upper 90's each day. The way I got around that was to take the boys to water park all afternoon (they get their showers), eat dinner in town and then fish the evenings and mornings. The swimming wore them out so they all slept well, even in the heat.
), the camp was super crowded, and the fishing was spotty. We did get one walleye in the boat, so I won't complain about the fishing. Just too much of a trailer park scene IMO...a lot of the locals I talked to said the place had gone to the dumps in the past few years. Now without my kids...yeah I'd hang out there all day and fish the flats for carp drunk off my ass.
