Blackberries can be grown here in the Uintah Basin but they need a sheltered location or extra winter protect/care. Some of the varieties we have seen growing here are:
Chester - Produces medium to large blackberries on thornless semi-erect canes. Floricane. Zones 5-8.
Darrow - Produces small to medium blackberries on thorny vines. Hardier than many other varieties. Floricane. Zones 5-8 (Maybe 4b).
Prime Ark® 45 - Newer introduction to our area. Produces tasty blackberries on erect thorny vines. Prime Ark® 45 is a primocane variety that produces berries on new canes so there is less winter damage. Although the berries are produced on new canes, they produce fruit late in the fall and may not be ready if we have an early fall frost. Zones 5-8.
Triple Crown - Produces large tasty blackberries on thornless semi-erect canes. Floricane. Zones 5-8.
Information from unaffiliated websites:
Blackberry Management in Utah (USU)
Disclaimer: This is a listing of varieties that have performed well in the area. This listing does not guarantee that the varieties are in stock. Please call to inquire if an item is in stock or not.