It varies a lot each year depending on how rough a winter its been and the snow pack. During some drought years its been open as early as opening weekend in April. I can remember other years when the lake was mostly frozen over Memorial weekend and the charter boat was out trying to bust some of the ice off.
Usually Diamond is open around the middle of May but the way this winter has been and the fact that the lake sits at about a mile high, it would be a good idea to periodically check in with the resort for current conditions. Early June is a pretty safe bet but I'm wondering about the availability of camp spots. The word's out about the super fishing last season and once the kids are out of school (or maybe before) it could be tough getting a decent spot

. I haven't been to Diamond for many years but plan to go next season. Thinking about those big Rainbows and that spectacular scenery is too much to resist!