Ask-a-Dave's-Gardener: Flower Identification, 2 by JessJess

JessJess wrote:
Can anyone help me identify this? I live in Northern Colorado and I\'m seeing it everywhere (but of course, landscapers never put up little plaques identifying what they\'ve put in the garden bed). I know the yellow flowers in the background of these pictures are yarrow, but I\'m not sure what the pink flowers are. I\'ve included a close-up of a bloom, and a shot of some of the foliage as well.

I bet it\'s something simple that I\'m just not remembering, but I\'d appreciate any help y\'all can give me.

Thank you! And I apologize that the photos are sideways.