Authorities in New Mexico say a man accidentally backed a pickup truck over his toddler daughter, killing her, while he prepared to unload an all-terrain vehicle at a campsite.

Sandoval County sheriff's Lt. Keith Elder said Monday that 18-month-old Shantel Cordova died at the scene along a forest road near Cuba in northern New Mexico.

Elder says 34-year-old Ivan Cordova Jr. of Albuquerque and his father were working on an ATV in a trailer at a campsite Saturday evening. They needed to move a truck so the ATV could be unloaded.

Cordova told deputies he thought Shantel was in a nearby recreational vehicle with his girlfriend when he moved the pickup.

Elder says an investigation is underway, but there is no sign that Cordova was impaired.