SAN FRANCISCO (KRON) — A San Francisco park ranger was hit in the head by a glass bottle while patrolling the weed festivities atop hippie hill in Golden Gate Park Monday evening, according to police.

The 51-year-old ranger was sitting on an all-terrain vehicle around 7:15 p.m. in Sharon Meadow when a man snuck up behind him and struck him in the head.

The suspect is described as a 37-year-old man, who was later taken into custody by police.

The ranger was transported to Saint Francis Memorial Hospital with a headache, but was released within a few hours.

Police are investigating a motive behind the attack.