It’s just as much a river as Lake Pepin!! (Wide spot in the Minnesota) The opener is April 27 and I’ll be there. The fish are always on a tear the first few weeks after opener.
Concentrate on the north 1/3 of the lake. Shallow shorelines are the best. There are miles of great looking shore structure to work over. Pitching Jigs or Cranks, Trolling, Corking all work great.
I like to use the SD state park to access the lake on the opener. Save yourself a 15 mile run up the lake from Ortonville. Pay the entry fee (like 5-8 bucks a day or a season pass for 20 something) They have excellent ramps and fish cleaning facilities. (I probably should not have posted that because the place is never crowded, busy yes, but not crowded)
J.