Asked September 09, 2016, 10:33 AM EDT
Crook County Oregon
The English walnut is your best choice. Black walnuts may be successful in the right location.
The best time to transplant any tree is in the spring but they can be successfully planted anytime as long as the ground is not freezing. It is important to water newly planted trees on a regular basis to keep the roots from drying out. It is even important to water them in the winter 3-4 times as winter drought is a big killer in Central Oregon. https://www.hort.purdue.edu/newcrop/cropmap/oregon/crop/treefruit.html http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/20433/em8907.pdf
This is really not a good area for nut trees but the backyard orchard may produce enough for a family.
Here are some links to publications we have created specifically for Central Oregon. Consider Prineville in zone 5 or less, zone 6 in protected locations, so plants that are rated for these USDA hardiness zones will normally work but not always. Use the publications to select plants that you are interested in. These publications are not all inclusive. If you would like to see more publications we have many available at the Extension offices in both Prineville and Redmond. Most are at no cost.
http://extension.oregonstate.edu/deschutes/sites/default/files/Horticulture/documents/ec1622.pdf http://extension.oregonstate.edu/deschutes/sites/default/files/Deer_Resistant_Plants_EC.pdf http://extension.oregonstate.edu/deschutes/sites/default/files/ec1623-e.pdf
Though these links are not necessarily specific to your exact questions they should give you a good start as they include fruit trees, herbs and natives of which many are herbs with medicinal qualities.