Nature Hills Gardening Community

I recently ordered some Sugar Maples, 2 to be exact.  I know about the surfacing roots, so i will plant them in the back yard.  My question is this:

I will plant one on the the left and one on the right of the yard.  But I want these trees to create a canopy or a tunel in the center of the back yard.  What distance should i plant them from eachother to achieve this effect? 

This may be different from the recommended generic planting distance...but i dont know that either.

 Which Sugar Maple did you buy. The Acer saccharum  or Acer saccharum 'Green Mountain' ?

thought i knew, but i am checking on the exact one now

OK, they were not Sugar Maples.  I thought i ordered sugar, but they are Silver Maple.  Maybe the zone i am in, not sure.  We are zone 4.  they look nice, but i am hoping the oval shape they become will be enough to create that shaded canopy/walkway i wanted.  I planted them 18 feet apart.  I really wanted an arch way over some terraced steps in the middle of the yard.  these trees will be on the second level, and hopefully create a doorway feel between them after you get up the stairs and onto the high part of the yard.  WE shall see.  I guess i can always cut them down and try to manipulativly prune them to branch toward the center.

.....can I do that?