CRAIG, Colo. (AP) — A woman and her children stranded for two nights in the northwestern Colorado wilderness were found Thursday by aircraft after the 1-year-old daughter died, authorities said.

The three were found about a mile away from their vehicle as the mother was walking among sagebrush and not close to any road, Moffat County sheriff’s office Lt. Chip McIntyre said. The sheriff’s office said Kaylee Messerly, 36, and her daughter, 3, were taken to the hospital with exposure-related injuries, KCNC-TV reported.

The 1-year-old daughter had died before the family was found. The cause of death was not immediately known.

McIntyre said an oil field employee, who was not identified, discovered the woman’s vehicle about 6 miles (9 kilometers) north of Craig stuck in mud and snow. The worker called authorities Thursday around 8 a.m.

McIntyre said a search was launched immediately with the The Moffat County sheriff’s office and search and rescue. The aircraft that found the family was provided by Mountain Air Spray Co.

Deputies are investigating.