There are lots of small crappie along the dam at Hefner. Most guys are casting out, sinking to the bottom, and ticking the rocks coming in. You lose a lot of jigs. Fishing from a float tube is a lot more efficient. You're in the strike zone all the time, and you don't use many jigs. But if the wind is strong from the south, it's a no go. And there ARE some big ones among the little ones.
Anchoring a boat and vertical jigging works well also.