the sanctuary ends at the dam. anything you catch in the lake is fair game. i used to fish there with my dad for carp all the time. it used to have an incredible fishery, but one day it seemed like all the fish just packed up and left. if you fish the south side where the lake comes to a point and makes a river you should be good for rainbows, nothing to big but they are there.. it's a rock bottom on the west end of that area, and a sand/mud bottom on the east side. east side has a ton of fallen tree's too so prepare to lose some lures lol.
hope this helps. please let me know if your at all successful as i would love to take my dad there again. it used to be his favorite spot.