Tall Privacy Grass Needed for Zone 4

The house we bought has a back deck that anyone can see from blocks away and the way it is curved puts it about 8ft from a sidewalk. The deck sits approximately 2.5ft off the ground. We are looking for a tall grass that will mostly grow up instead of out given the constrain of the sidewalk, and will reach somewhere between 7-10ft in height.I keep thinking I have found something, but it's hard to tell when you find heights for the same grass ranging from 7 feet on one site to 3 feet on another (Well which is it already!? grrrrrr!!!!) Does anyone have any suggestions? Suggestions from grasses you have dealt with or personally seen would be the most helpful.
I didn't have a real picture so I just pulled one from google maps. Ignore all the weeds and the tree. They are not there any longer. The weeds because ick, and the tree because it was trying to break into the basement and we had to chop it down in order to get insurance on the house.

Heights of ornamental grasses are given as such a wide range because the leaf mass tends to grow at the lower height, and the flowers stand on stall stems above the leaves.
So, a grass shown as 3'-7' means most of the leaves tend to stay about 3' high, and the flowers can reach 7'.

Anyway, tall grasses: I have NO idea if they grow in your area!
Miscanthus
Muhlenbergia rigens
Stipa gigantea
Panicum virgatum
Leymus condensatus
Sporobolus wrightii

Alternate ideas: Narrow shrub, and plant a couple of them.

Thanks for the suggestions!

Calamagrostis (a red-tufted cultivar - I forget which one) and miscanthus sinensis (grosse fontaine) worked wonders for me in Zone 5. Also, they added interest to the garden during winter, poking through the snow. They were not invasive and always survived winter well.

Sylvain.

Take a look at Miscanthus giganteus.

This is a very tall ornamental grass which won't set seed and become a pest. It is hardy into Minnesota, so may very well be suitable for your growing conditions in zone 4 North Dakota.

I don't think any of the other species mentioned will meet your 7-10' height requirement.

Thanks!