I've stayed at a dozen or so Elks lodges in the western States. It's a great benefit and prices are very reasonable (usually $15-25). Most are just in a section of the Lodge parking lot, so don't expect "destination" camping or a rustic campground kind of feel. Some are nicer than others. Some have camp hosts. Usually I'm just there to do sightseeing or visit friends, so I don't mind being in a parking lot. Most have spaced the sites nicely. In Oregon, Florence and Tillamook actually have very nice off-site RV parks in park like settings.
Since most are first-come first-served, I call a day or two ahead to see if they're busy, and always have a back-up plan.