If you're looking for some of the western prairie birds, the Pawnee National Grassland is a good area for Burrowing Owl, Mountain Plover (both on Prairie-dog towns), Ferruginous and Swainson's Hawks, and Lark Buntings. There should be both Chestnut-collared and McCown's Longspurs, as well, but when I was out there last month I didn't have much luck with them. It's a ways north of I-76. For specific locations out there, I'd suggest checking e-bird, since my own experience is pretty much 20 years out of date.