Saturdays at Northstar are way too crowded. This is just a way to thin the crowd by keeping away the people who weren't spending much.
Actually, I found that Northstar works like rush hour traffic jam on Saturdays. The LONGEST wait is the 930am-1030am wait at the bottom of the mountain.
I either get there by 9am. Ride, but NEVER back down to the bottom until it's lunch time. Or get there by 11am and just call it a half day.