Lots of people were out this weekend, and it sounds like things are really happening on the rivers.
Rock River: Fish were being caught from the mouth at Blackhawk up to the dam at Jefferson. Sounds like there were some solid bags of keepers in the batch this weekend. Expect it to stay good as fish move in and head up to spawn.
Controlled drifts with jigs or 3 way rigs are always solid approaches on the Rock for the spring. You really want to concentrate on hard bottom spots, or areas where the main channel turns or changes direction. Deeper isn't always better (fish can be out of the channel) but a transition forms a pocket where fish will stack up.
My favorite stretches are in the S-Turn ditch, just down stream of the Jefferson Dam Launch,by the Star Pole and just downstream of the Fort Bridges, but there's no limit on areas that will hold fish. Just remember the water is still cold, and often a bite doesn't feel like much of anything other than just a little additional weight.