HELENA, Mont. (AP) — The U.S. Bureau of Land Management has approved building a 5 ½ mile natural-gas pipeline in the Upper Missouri River Breaks National Monument.

The BLM decision released Friday says there will be no significant impact to the monument if the installation is completed under certain conditions.

They include restrictions on installing the pipeline while big game winters in the area or in the spring, when bighorn sheep are lambing. If workers find any cultural or paleontological items, they must halt work immediately and report them. They also must seed the ground they disturb.

Sleepy Hollow Oil and Gas and Kykuit Resources propose building the underground pipeline from a federal well about 20 miles north of Winifred in Blaine County to an existing line between two other wells.