The genus Pseudacris has several species represented in Oklahoma; but I can't exactly match your frog characteristics to any of them. P. maculata, the Boreal Chorus Frog did came close. There is the possibility it is a naturally occurring hybrid, since they are known to happen when the species overlap. But your frog's apparent large size has me thinking something else.

If your location was to the West; P. regilla, the Pacific Treefrog would be my call. They have not been reported in Oklahoma as far as I know; but have been found eastward to Idaho, Montana, and Nevada. Maybe someone released some specimens at your location and they have bred in there. Would appreciate if you compare your frog to pics in the link to AmphibiaWeb and tell us what you think. Couple photo's from above and side of head would help get better ID; but I'm going with a PTF for the time being .