I'd look up the Wyoming soil conservancy district office that covers where your land is. If its anything like Colorado, they will have a tree program with appropriate trees, weed barrier, deer protectors, and pretty much great advice on what to do for your specific location.

I might also suggest that you contact Tom Heald at www.wyomingplantcompany.com. He is a retired extension agent who did the "from the ground up" segment from UW on TV for years. He recently started his own nursery here in Casper so he does sell trees, but he is also a wealth of information whether you buy from him or not. His website has some good info on the types of trees he sells.

Rocky Mountain Juniper are a great start on the lower levels of a windbreak and may even be able to survive without water after establishment depending on the soil type you are purchasing. Caragana will also survive well, but needs supplemental water.

Beyond that, unless you will be on a creek where there is groundwater, any trees you plant will always require irrigation. Cottonwoods are native but like water. They make wonderful shade trees, however. Chinese (Siberian) elms are widely planted because they survive almost anywhere (including around Casper), but availability of water will determine their height--70' or more if water is not limiting, 10' if it is highly limiting. They are probably one of the most common trees in yard plantings in the non-mountainous parts of Wyo. because they survive so well. Other than being trees that survive, they don't have a lot of other reasons to plant--little fall color, no attractive blooms in the spring, they will drop a gazillion little seeds that will sprout in all your garden/flower beds in May leaving you weeding them out the rest of the summer. But--they DO SURVIVE!

Russian Olives are widely planted because they will also survive almost anywhere and if you don't have to get into them to get past the thorns or keep them pruned up, they make a very attractive tree. They are also considered noxious in many areas these days because they are so invasive along streams. Kentucky Coffee trees are often recommended but rarely seen.

Chokecherries and native plums are wonderful small trees but will require supplemental irrigation, and lilacs and clove currants also do very well if given supplemental water.

With irrigation, you can also plant blue spruce or pines, great for blocking the wind although these are slower growing and better to get them going now so that they can be reaching a useful height in 10 years.

Talk to the Natrona County Conservation District about low cost trees for your windbreak.

Plant your windbreak to the north and west of the homesite to break the wind unless you like walking at a 45 degree angle and hate raking leaves. Do a search of windbreaks to get some very good explanations of the engineering of windbreaks.