Some 200 protesters gathered at US President Donald Trump's golf course near Los Angeles and spread out in the grass to form the word "RESIST!"
A group calling itself "Indivisible San Pedro" organised the demonstration on Saturday at a public park nestled within Trump National Golf Course in Rancho Palos Verdes.
Peter Warren, a retired journalist, told the Los Angeles Times the group wanted to protest Mr Trump's policies and urge the release of his tax returns.
He says it took 15 minutes to form the 30-foot-tall letters, after which they sang "God Bless America".
Mr Warren said it would have been too hard to spell out "release your taxes" so they opted for "resist" instead.
He said golf course officials and sheriff's deputies watched from the clubhouse but did not intervene.