Wish I could tell ya, but I've been in Wyoming for the past 2 years. If I had to guess, and just a wild guess, that run has been in effect for a little bit, maybe until mid-late Apr. Again, just my guess.
Yeah it happened. I was there several times from Dec thru late Feb. Good time if you can make it. Never been this late though. The whites are good at Canyon. Been catching them pretty good since early March.