MEDORA, N.D. -- About 650 barrels of saltwater and 20 barrels of oil spilled from a well site 15 miles northwest of Medora in Billings County, the North Dakota Department of Health announced Monday.

Some of the brine and oil reached a tributary to the Little Missouri River about 4.5 miles west of the river.

The spill, on private and U.S. Forest Service land, has been contained.

Midland, Texas-based BTA Oil Producers LLC reported the spill Sunday, and is evaluating the extent of the spill and how to fix it, along with the U.S. Forest Service and the health department.

A barrel is equal to 42 gallons.