C.P.
Lake Murray in OK is only about 1.5 hr from the Metroplex and has lots of activities--golf, tennis, horseback riding, canoeing, paddleboats, plus you can tent camp, RV camp w/ hookups, cabins w/ a/c & indoor bathrooms, or stay in the beautiful lodge. I've been several times over the years & it's a lot of fun. The water is very clear, as well.
http://www.touroklahoma.com/detail.asp?id=1%2B5U%2B6446