What type of shrubs or evergreen trees would make a privacy barrier fo

Arbor Vitae is most common evergreen hedge

I live in Mich and have arborvitae growing around the entire perimeter of my yard. It is fast growing and virtually maintainance free. You can trim the top off if it grows too tall but it will grow back nice and even.

Pyracantha (Firethorn) is evergreen with about 4-inch long thorns. Takes a while to grow, but a fantastic stock-proof hedge when fully grown. Takes a while to clip too, but don't they all?

http://blog.cleveland.com/pdextra/2010/05/experts_recommend_privacy_plan.html

We have arborvitise along the back of our yard. It gives us privacy

Evergreens! Arbor vitae, Colorado blue spruce, Austrian spruce.