One of the best April Fool's Day hoaxes occurred near Sitka, Alaska. Sitka is a small town in Southeast Alaska near Mt. Edgecumbe, a volcano that has not seen an eruption in several thousand years. In 1974, a local resident, Porky Bickar, hauled a bunch of old tires to the top and lit them on fire. Residents awoke to see smoke coming out of Edgecumbe and worried that Edgecumbe had awakened from its slumber. Bickar had alerted some authorities in advance and also painted April Fool's Day near the top of the volcano. Legendary.
https://en.wikipedia.org/wiki/Mount_Edgecumbe_(Alaska)