The Heart of Southeastern Oklahoma Situated in the foothills of the Ouachita Mountains , McAlester, Oklahoma is a vibrant small city with a big reputation for history, hospitality, and opportunity. As the county seat of Pittsburg County , McAlester serves as a central hub for commerce, culture, and outdoor recreation in southeastern Oklahoma. With a population of over 17,000 residents , it’s one of the largest cities in the region—offering the convenience of modern amenities with the warmth of s