Blackberries in Colorado
Will blackberries grow in Colorado's Northern cold dry region around Livermore? (NW of Fort Collins)
Wilbarger County Texas
Blackberries grow quite well along the front range, but they do need some extra water and in some locations, winter protection. Depending on your site, you may be able to grow them successfully. Raspberries are shown to be more cold hardy.
In Longmont, we grow three varieties of blackberries with great success: Triple Crown, Prime Jim and Chester. Triple Crown bares huge, sweet berries and they are thornless which is a huge plus. Chester is a similar variety and both are relatively cold hardy (zone 5-9). Blackberries prefer a higher pH soil than our native soils so you would probably need to amend with organic matter.
Being in a more rural area, you will need to protect the fruit from birds, rabbits, deer, etc.
See the fact sheet at the link for more information on growing raspberries. The same principles would apply to blackberries.