Mogami clan
The area of present-day Ōkura was part of ancient Dewa Province. During the Sengoku period, the area was under the control of the Mogami clan. During the Edo period, the village was a river port on the Mogami River and a post station on the pilgrimage route to Mount Gassan. After the start of the Meiji period, the area became part of Mogami District, Yamagata Prefecture. The village of Ōkura was established on April 1, 1889 with the establishment of the modern municipalities system.