A woman was killed when her pickup truck drifted off a country road Tuesday morning in far western Hennepin County and struck a tree, authorities said.

The crash happened sometime before 9 a.m. on Pioneer Creek Road, about 4 miles west of Maple Plain, according to West Hennepin Public Safety.

The identity of the woman was being withheld pending notification of relatives.

The pickup was heading east on Pioneer Creek, when “for whatever reason” it went into the ditch and hit the tree, said Gary Kroells, West Hennepin’s director of public safety.

There were no witnesses to the crash, but Kroells thinks it happened not long before passersby reported it to authorities.

Kroells said it was uncertain whether the woman was wearing her seat belt at the time.