Pittsburg county is located in southeastern Oklahoma with McAlester, named for merchant and entrepeneur Col. J.J. McAlester, serving as the county seat. After the Civil War, McAlester located the first outcroppings of coal in the area and was influential in bringing the railroad through Bucklucksy--later to become McAlester.

The Canadian River forms the entire northern boundary with Hughes County and McIntosh County on its journey east to join the Arkansas River. Other major waterways are Eufaula Lake, of which about half is located in the county, and Lake McAlester which lies just east of the Indian Nation Turnpike.

The major employer in the county is the U.S. Army Ammunition Plant southwest of McAlester. It utilizes about 1,200 workers.

Some historical sites in the county include the McAlester House on E. Smith Av. and the Canadian Jail and Livery Stable in Canadian.

The county population on July 1, 1999, was 43,472, an increase of 2,522 over the 1990 census.