I haven't been to Hagg since it's been open year 'round. The season opener used to be the first Saturday in March each year.
Back then the best success, trolling, was flat lining the surface and crossing over the creek inlet drop OFF's. In other words using light gear, with very little weight, and line trailing about 75' behind the boat.
From the bank I'd make sure that my bait was floating into the top 5' - 10' feet of the surface. I typically dunk was OFFering close to the bank; for those fish that are following the shore line foraging for food. Then toss the other line, with heavier slip sinker, out much farther. Just in case any are out there and hunkered down in the cold. (I've gotten the 2-rod endorsement, ever since it was OFFerd).
Good luck and let us know how you do.