I don't know how old the resort is, but definitely less than 20 years, probably about 10 years.
It is rural and isolated, with its own interstate exit, but there appear to be 3-5 other NA casinos within an hour's drive, so there's enough choice in the area to keep them competitive in their offerings (IMO). Wichita and OK City are probably about as convenient as KC. It took 2 1/2 hours to drive via interstates from Kansas City International airport Springfield MO is closer, but somewhat less convenient to flight schedules. The resort (and it deserves the name) is located in the corner of the US where Kansas, Missouri, and Oklahoma meet, 10 miles west of Joplin, MO.
We had an excellent time there in most all respects, and so I wanted to provide a write-up for future patrons. I went to SE Kansas for a family event the last week of March 2015, escorting my mom, and we stayed two nights at the Downstream Casino Resort in Oklahoma.
