Hello,

You don't state whether you'd prefer evergreens or deciduous shrubs, but below are a few options. 

I would point you to the columnar tree fact sheet, as there are "trees" that could be considered shrubs: https://extension.colostate.edu/topic-areas/yard-garden/columnar-and-fastigiate-trees-for-co-landscapes-7-427/

And the one on hedges: https://extension.colostate.edu/topic-areas/yard-garden/hedges-7-208/

There are many juniper cultivars that would fit your specifications:

Blue Point

Hetzi Columnar

Spearmint

Cologreen

Medora

You could also consider North Star spruce, Compact Gem Bosnian pine, upright mugo pine, privet, Siberian peashrub, columnar buckthorn, or Snowball viburnum.

These are all 12+ feet tall, but will vary in width. Good luck!