Laguna Coast Wilderness Park has less vegetation among the hiking trails, oaks and sycamores.
Orange County Sheriff's Department narcotics investigators pulled 2,500 to 4,000 marijuana plants out of the park's Muddy Canyon area Aug. 15, according to a department news release.
Sheriff's Lt. Jeff Hallock estimated the total street value at $3 million.
As of Thursday detectives had not identified any suspects, Hallock wrote in an email.
"It is going to be extremely difficult to develop additional suspect information now that the plants have been eradicated," Hallock said. "Our hope would be a lead from somebody who has information about the person(s) responsible for the grow."
Investigators hiked into the rugged area south of the 73 Freeway near East Coastal Peak Park and Ridge Park Road to remove the plants, the release said. The Sheriff's Department's airship "Duke" then flew the pot to a staging area to be packaged for evidence.
An OC Parks ranger happened on the marijuana, clumped in two areas, and alerted authorities, Hallock said.
The number of plants is not unprecedented, Hallock said, although it is unusual for such an amount to be near residences.
"In the past we've found plants deep in canyons, such as off Ortega Highway, in more rural areas," he said.
Anyone with additional information is asked to call the Sheriff's Department at (714) 647-7000. Anonymous tips may be submitted to Orange County Crime Stoppers at (855) TIP-OCCS (847-6227) or http://www.occrimestoppers.org.