Gallup, New Mexico is about halfway.
Grimes, Oklahoma is halfway between Alamogordo and Buffalo
Winslow, AZ
The halfway point would be Mora New Mexico. The closest major city to the halfway point is Albuquerque New Mexico.
McKey, Oklahoma.
eh someplace south of Pueblo and north of Trinidad... out in the nowhere between the two.
Lebanon, Missouri
The distance between those two points is 884 miles and while Amarillo is 600 miles from Houston and difficult to term a halfway point, it the preferred stop over point on that route.
Seminole, OK. The nearest city is OKC.
Albuquerque, NM..
That would be Albuquerque, New Mexico which is 544 miles from Oklahoma City and the true halfway point would only be 503.5 miles.
The halfway point between 5700 and 5800 is (5700 + 5800) ÷ 2 = 5750