Hi copuswalker,
Have been watching this one was getting ready to add my 2-cents worth. I think this is the right spot.
First off, I agree with what's been said so far. Dinosaur Valley is a great SP and I really enjoy going there. Swimming in the Paluxy River in the latter spring and early summer is outstanding. From a spot called "Blue Hole", a rather deep pool, on down as far as about Track Site #3 you have nice swimming and wading. As said though, as the summer wares on, all of the three rivers in that area get very low, slow and hot. Not a great place to be swimming at that time. They have this same issue with swimming in Onion Creek at McKinney Falls SP in Austin. There, they test the water and close it to swimming as needed.
Also, I feel I need to warn you about temps in this park. Park is situated in a low spot and gets little breeze. Have found park to be very hot in the summer. Have camped there often in the fall, winter and spring and have always enjoyed it. Also like to use park for a late spring/early summer picnic/swimming trip. We do these "day trips" by arriving at park around 8am. and then leaving not later then 2 pm to avoid the heat. My grankids love it.
As far as Cleburne State Park goes, I'm for it! We live within 35 minutes of it and camp there very often. With the exception of the shower houses that could use a bit of work, this is a great park.
As far as swimming goes, the lake is spring fed and doesn't loose a great deal in the summer. We were there last month and the lake was in great shape with a pretty good volume of water flowing in the creek that feeds it. I don't use the standard swimming beach, as most don't that know the park. Much nicer to follow the road around to the far end of the park where the "full hook-up" camping sites are located. Swimming off the beach behind camping sites 45, 46 & 48 is the best. Of course, if there are people camped there, they may rightfully object
! There's nothing wrong with swimming at the approved beach but the other area is nicer.
Hoped this has helped some and you have a great trip no matter where you end up. Happy Camping!