 In 1971 and 1984, dolosse were added in two layers to secure the jetties, which are maintained by the U.S. Army Corps of Engineers.In 1972, 4,796 dolosse were manufactured locally; 4,795 of them are on the jetties, and one was installed outside the Eureka Chamber of Commerce.In 1983, 1,000 more dolosse were made at the South Spit yard and left to cure; local newspapers named the curing site "Humboldt's Stonehenge."