If you want an extremely common tree bareroot, your best bet may be your local County Soil Conservation Office or a State Nursery from a state near you. They are cheap and likely grown in your zone. Avoids problems with trees that spend a long time in trucks or are shipped from a zone south of you where they may break dormancy before your ground is thawed.

Itasca Greenhouse is a great source for seedling plugs.

For bareroot, consider Flickingers

I have never ordered from Vans Pines but they look interesting as well with a ton of species to choose from.

Another one which I've heard good things about but never ordered from is Needlefast Evergreens

What sort of project are you planning?

Vans Pines in Michigan: I have had very good plants from them and will order from them again.

I have also had good plants from your state of Wisconsin.
Evergreen Nursery, Sturgeon Bay, WI.

All, thanks for the suggestions! I'm planning to plant Picea omorika on the lot lines. Just seems to be the right spruce for around here.

bax, Evergreen Nursery is wholesale. Is there a retail link that I might be missing or did you just call them to get an order in?

Whaas: Sorry about that. I am able to order wholesale for my nursery.

Perhaps you can find someone local to work with that will order them for you.