There's no set time for the run.. can happen anytime from the end of April to first week of June. Peak run seems to be when the water clears up after the spring flood.. when you can see the caddis larvae trails in the sand on the river bottom... lol.. you'll get some both before and after that of course but I'd say that's when it's best. Obviously how far you are fron the ocean is a factor as well.... I catch em behind my house 3 weeks before they make it to my camp... I live on the Keswick river and know they school up in the St John at the mouth til the water clears.. then I get a few days of magic.. ! Doesn't last long... I fish everyday.. only way to be sure to hit it. Good Luck !
It's hard to tell. Last year with all the flooding, they started moving up early and tended not to hang out at the pools and just moved straight up river. This year, we didn't have a freshet to speak of, so it's gonna be interesting to see and take not of for future references. Like Troutbum said, you're gonna have to fish every day at all your favorite pools and try to narrow down where they are. Once you find them, it's just a matter of following them up river from that point on. They'll tend to move on up river with every rain, so if you happen to come accross them, they'll be there until the next rain, or until the gaspereau force them up river.