A Twin Cities man riding among a group on ATVs in a northern Minnesota forest struck a tree and was killed, authorities said Tuesday.

The crash occurred shortly after 6 p.m. Monday in the Paul Bunyan State Forest, according to the Hubbard County Sheriff’s Office.

The victim was identified as Aaron Sly, 26, of Bloomington. Sly had on a helmet but still died from “serious head injuries,” the Sheriff’s Office said.

The Sheriff’s Office pointed to “excessive speed” by Sly on the four-wheel ATV as a factor leading up to the crash.