Police established a perimeter in Griffith Park, just south of the 134 Freeway, after receiving a call for help from a park ranger.
Officers and several squad cars were at the park entrance near Forest Lawn Drive and Zoo Drive (map) into Thursday afternoon.
The search began after flower vendors threw rocks at the ranger, according to police. Vendors often sell flowers near the 134 Freeway entrance and exit ramps on the side Forest Lawn Drive.
The ranger, who suffered a cut to his arm, was treated at the location.
An LAPD airship and canine unit also responded to the call. The team searched for more than two hours, but no arrests were reported late Tuesday afternoon.