Crappie are pretty unpredictable in Oregon (along with most of the fish I guess). We usually go to Prineville Reservoir and hear that the crappie fishing is really good when you find them, but I haven't seen a Crappie caught out of Prineville, but then again I have only fished out of a boat once for bass in there.
Snake River is a 7 - 8 hour drive that is completely worth it, I usually get sick of catching 14 - 18 inch Crappie and switch to Smallmouth fishing, and we usually use bass plugs to catch the 22 inch Channel cats (I haven't caught a catfish in the Snake River using bait), I never had any knowledge for carp back in the days I fished the Snake River, but they are everywhere, including on the bank every 15 feet (which is how I found out what a carp is). I have seen some big Perch come out of the Snake River, one was about 15 inches.
Most of the Crappie I have ever caught were hanging out under little shack boats, and under overhanging trees, usually just under any kind of shade feeding on minnows.