Answer: Based on your zip code, you are gardening in zone 5A. Depending on your microclimate it might actually be as cold as zone 4. For this reason I would suggest you select plants rated hardy to zone 4. A berm planting site is usually quite dry due to the abrupt slope, so you will need plants that can tolerate that as well. Your selection also depends on the type of soil in your berm, the amount of space on the berm, the surrounding landscape, and your personal taste.
Please understand that deer resistant does not mean deer proof. Deer learn to eat new plants all the time, so if they are browsing in your landscape now they may well develop a taste for plants that are elsewhere considered deer resistant. In my own experience, the only reliable long term solution is a tall fence. Some people have success with the spray-on repellents sold at garden centers, but these can be a chore and expense if you have a large area to cover as they must be applied (and reapplied!) per the label instructions or will not be effective.
You might have some success with plants such as burning bush (Euonymus alatus "Compactum"), smoke bush (Cotinus coggygria), a hardier forsythia such as "Spring Glory", lilacs, and toward the base of the berm where it will naturally be damper, Ilex verticillata. There are no evergreens on my list because the deer seem to prefer these, except for boxwood. Boxwood however needs protection from the winter winds to stay green and survive the winter. There are a few varieties considered hardy to zone 4, but they may not blend well in the design sense with the other plants listed above, because their natural shape is so regular and "formal". (It depends on your overall landscape style, as they can certainly be used together.)
Your local professional nursery staff and/or county extension may have some additional/different suggestions based on local experiences with the deer. Your neighbors are also a good resource for learning what the local deer have learned to eat so far.
The ornamental grasses do not seem to interest the deer. I am not sure what you are thinking of in terms of feathering. All grasses bloom at some point in the season, some earlier and some in the mid to late fall. Some that are hardy into zone 4 would include Festuca glauca such as "Elijah Blue", blue oat grass (Helictotrichon sempervirens), Calamagrostis such as "Karl Foerster", Panicum virgatum such as "Heavy Metal", and Pennisetum alopecuroides such as "Hameln" and "Little Bunny". As a rule of thumb, the grasses do better on the lower part of a berm where it is naturally moister.
I hope this helps.
Good luck with your project!
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