whitefish depth in late March?

[shepike]

I'm from Alberta, trying to get my first whitefish, have all the gear and tips. are the whitefish shallow this time of year? what kind of bottom  and or structure do they like? flats?

any advice would be great! I;ve seen them on sonar, passing by but none stick around. although I havent spent a day just targeting them.

cheers!!