On my trips to northwest AR in the 1970s, KSYN had a solid signal. Same with Springfield stations like KTXR, KWTO-FM and KTTS-FM.
I went to college in Fayetteville for a couple years in the 90’s. I could get KSYN, KOBC 90.7, WMBH-FM/KJKT 102.5, and KIXQ 93.9. KWXD 103.5 and KOCD 105.3 were surprisingly easy to receive there, too. 97.9 and 107.1 were about the only Joplin area stations at the time that I never got there. I always got KZBB on 97.9 and KTHS-FM on 107.1. I also got 96.9 from Pittsburg.
KTXR, KKHT/KWTO-FM, and KXUS were easy to get in Fayetteville, too. By the time I got there, it had a local 94.9, which aired southern gospel as KDAB “The Higher Power.” It, however, signed off at 10:00 every night. Once it signed off, KTTS usually bled into 94.9 and came in like a local. That would be when I would start getting KMXL 95.1, too.
Until KBTN-FM signed on at 99.7 in the summer of 1995, I frequently got KLTH out of Kansas City. KREB 99.5 had just returned to the air, but it had a poor signal around Fayetteville. It was usually listenable, but it got interference from the 99.5 out of Tulsa and didn’t cause much interference itself. KBSY 107.3 got bought a few months after I got there and, after switching to gospel and country, it also began signing off at 10:00. KISF 107.3 from the KC area would usually blast in underneath it. A handful of Tulsa and, as I mentioned above, Ft. Smith stations came in pretty easily in Fayetteville, too. 103.3, 104.5, and 106.1 were the Tulsa ones I often got. KISR 93.7 was almost a local in Fayetteville. 97.9, 99.9, 100.7, 102.7, and 107.3 were the other Ft. Smith stations I consistently got on my home stereo. KMAG 99.1 came in much of the time but wasn't consistent. I could never figure out why that was.