Arcadia Lake is a great little lake north of Oklahoma City about 30 minutes. It is definitely a weekender party lake, but the campgrounds are well maintained and facilities are kept up well. There are trails, boat ramps, and 'beaches,' but we go for the two disc golf courses. There are two back to back courses that are really well maintained, and are well designed. Whoever mows the course must play disc golf because they do a great job of defining the fairways. The courses are definitely worth the $6 fee to enter the park.
P.S. There are quite a few ticks out in the summer time. So bring the bug spray if you'll be in the tall grass at all.