The plants covered the size of a football field and could produce 25 to 50 tons of marijuana, with a potential street value of $300 million, U.S. Drug Enforcement Administration Agent Amy Roderick said.
A deputy spotted the field late last week in the remote mountain area south of Paso Picacho campground in Cuyamaca Rancho State Park.
The final plants were removed Thursday. Most of the pot will be destroyed with a portion kept as evidence.
There have been no arrests.