HUNTINGTON BEACH, Calif.—A reptile believed to be struggling in sand at a Southern California beach was simply making history: a sea turtle laying eggs on the U.S. West Coast.

And three days later, there were more. An olive ridley turtle—maybe the same one—laid eggs on Sept. 19, a few miles away near the Huntington Beach Pier in Orange County, authorities said.

“This is the first-ever recorded natural nesting for any sea turtle species” on the West Coast, the National Oceanic and Atmospheric Administration’s West Coast Fisheries division said on Facebook.

Olive ridley turtles are the smallest of sea turtles, with adults weighing up to 100 pounds. NOAA said they’re found worldwide but primarily in the tropical waters of the Pacific, Indian and Atlantic oceans.

The first nesting spot was near Seal Beach on Sept. 16, followed by the discovery at Huntington Beach. Both sites were subsequently fenced off. Incubation typically lasts 45 to 60 days, NOAA said.

“We’re excited about it,” said Trevor McDonald, marine safety chief at the Huntington Beach Fire Department.

Lifeguards patrolling at night saw a turtle digging in the sand and thought “maybe this turtle is sick. We just don’t see this very often,” McDonald said. “Then they observed the turtle starting to lay eggs.”

Heidi Stephen said her 9-year-old son, Jude, begged her to take him to Huntington Beach to see the nest Tuesday.

“It’s so magical,” Stephen said.

George Zamora said he hopes the eggs can survive any impact from tides, storms and popular beach events.

“Let them do their thing,” Zamora said. “Let them be born.”

By Eugene Garcia and Ed White