Shadegardener said: first and foremost is to choose a tree that can grow in your soil.
I don't live in Idaho...
So... I wouldn't know what would survive your winters...
In many parts of the country, there is a clay that is referred to as 'gumbo' clay... and trees grow in it...
starting with a small tree or a seedling definitely improves the likelihood of success... matter of fact, I'd seed plant if at all possible!
Information that would help get better responses...
what kind of trees you have in mind?
fruit trees?
conifers?
there are government agencies created to help american gardeners choose good varieties and plant them in the most likely way to succeed....
try the extension service:
https://www.uidaho.edu/extensi...
