Hi Kirk,

That's some good looking grass!  From what I can see, it's a type of "feather-reed" grass called Karl Foerster grass (Calamagrostis x acutiflora 'Karl Foerster'), named after the German horticulturist who bred and introduced it into commerce.

They are pretty easy to care for plants--simply cut them back in the dormant season whenever they start to look ratty.  This is often after a heavy snow that flattens the dried stems.  Cut them back at the latest in the early spring, typically mid-March, to make way for the new growth.  You can cut them to about 4" up from the ground.

As the clump grows, you may see that the center is beginning to die out, making more of a donut-shaped ring than a tight bundle of grass.  To counteract this tendency, you can, using a shovel, take a pie-slice out of the clump every year or two to make sure that the grass in the center still has access to light and air, with room to grow.  

For more information about ornamental grasses, including Karl Foerster, please see: https://extension.colostate.edu/resource/ornamental-grasses/

I hope this is helpful!

Cordially,

John