Colt, here is what is listed for Union County in "Complete Angler's Guide to Oregon" by John Shewey.
Catherine Creek Slough: bucketmouth bass, white crappie, perch, smallies, channel cats, 'gills and more.
Grande Ronde River: large and smallmouth bass, crappie, perch and 'gills.
Grays Slough: black & white crappie, and bucketmouths.
There is also quite a list of "Bass & Panfish" waters in "Fishing in Oregon" by Maddy Diness. There's too many to type. May I recommend that you get a copy, of this great book?