Both, plus Canadian and Pottawatamie Counties.
It is 99.33 miles according to MapQuest.
The population of Oklahoma County, OK on December 21st 2011 is approximately 723,402. (Extrapolated from a population of 660,448 in 2000 and a population of 718,633 on February 16th 2011.)
McCurtain County at 1,852.
It has a population of 701,807 residents.