Agreed that you want to push back as far as possible. I think you're in the same belt as me as far as snowfall amount - I plan for 76" average for the season. You'll also have to do your planning for piles around what type and location of accounts you have. I usually plan the push so I don't have to worry about what I'm pushing into since there is a lot of wide open space here. If your pushing city business or residential, obviously you'd have other considerations. For an average push of 50', I'll usually push back at least 15-20'. But, also, I don't stack very high so my piles are low and wide. You might come at it from a different perspective - how many "pushes" do you need to allow for? Again, I allow for an average of 6" per push (or snowfall) and base it on 12 pushes per season (6"x12=72" - compare to 76" seasonal average). Now, figuring I can put every other push on top of the one before it, I need to allow for six pushes. Now, obviously, if you're stacking higher, using a loader/backhoe or hauling snow away, you'll need less area. Me - I've learned to keep the tires off the pile.