Saturday, 26th. Travelled about 18 miles, and missing our road, encamped on the North fork. At noon we passed the best grass I had seen since I left the frontier of Missouri; it was like a meadow, kind of blue grass — found buffalo, killed three.

I don’t know if this grass was buffalo grass, but it well may have been, since that was the predominant prairie grass. According to Native American Seed:

Buffalograss is interwoven into American history. Starting with fossil remnants found in Kansas dating back 7 million years ago. Buffalograss (Buchloe dactyloides) was and now once again is the principal forage grass for the American bison, hence the name. Early settlers made use of buffalograss for building their sod homes, while the longhorn cattle grazed it on their way up the Chisholm Trail. It is an important part of the short grass prairie ecosystem. For homeowners with conservation awareness, Buffalograss has become a recognized alternative for turf like lawns.