Soap Lake is in eastern Washington roughly midway between Seattle and Spokane. It’s just a short drive off I-90. A city owned RV park is right along the lake, with its waters regionally famous for their healing properties — take a swim and get better from a variety of ailments, or so the promise goes.
The town of Soap Lake isn’t much, a short main street with a few shops that somehow manage to survive. But there are a few restaurants, a bar or two, and everything is a short walk from the RV park. Another couple blocks beyond Main Street is the nine-hole Lava Links golf course, where you can play for free. But if you have good clubs, then it may not be an idea: there is no grass, just hard-packed dirt, sagebrush and volcanic lava outcroppings. Ask for some loaner clubs at City Hall, which is across the street.
The RV park has hookups, and a campsite is inexpensive, less than $20 a night in prime time. It’s a good place to spend a day or a week, and maybe take a dip in the lake to improve your arthritis.