Moon rocks encased in acrylic and mounted on a wooden plaque at the Clark Planetarium, in Salt Lake City, Utah. A former NASA investigator who has spent more than a decade tracking missing moon rocks is closing in on his goal of finding all 50 lunar samples given to U.S. states after Neil Armstrong’s first steps on the moon. (Rick Bowmer/AP)

A strange thing happened after Neil Armstrong and the Apollo 11 crew returned from the moon with lunar rocks: Many of the souvenirs given to every U.S. state vanished. Now, after years of searching, a former NASA investigator is closing in on his goal of locating the whereabouts of all 50.

In recent weeks, two of the rocks that disappeared after the 1969 mission were located in Louisiana and Utah, leaving only New York and Delaware with unaccounted-for rocks.

Attorney and moon rock hunter Joseph Gutheinz says it “blows his mind,” that the rocks were not carefully documented and saved by some of the states that received them. But he is hopeful the last two can be located before the 50th anniversary of the Apollo 11 mission next summer.

“It’s a tangible piece of history,” he said. “Neil Armstrong’s first mission ... was to reach down and grab some rocks and dust in case they needed to make an emergency takeoff.”

Many of the Apollo 11 rocks have turned up in unexpected places: with ex-governors in West Virginia and Colorado, in a military-artifact storage building in Minnesota and with a former crab boat captain from TV’s “Deadliest Catch” in Alaska.

In New York, officials who oversee the state museum have no record of that state’s Apollo 11 rock. In Delaware, the rock was stolen from its state museum on September 22, 1977. Police were contacted, but it was never found.

President Richard Nixon’s administration presented the tiny lunar samples to all 50 states and 135 countries, but few were officially recorded and most disappeared, Gutheinz said.

Each state got a tiny sample encased in acrylic and mounted on a wooden plaque, along with the state flag. Some were placed in museums, while others went on display in state capitols.

But almost no state entered the rocks collected by Armstrong and fellow astronaut Buzz Aldrin into archival records, and Gutheinz said many lost track of them.

When Gutheinz started leading the effort to find them in 2002, he estimates 40 states had lost track of the rocks.

“I think part of it was, we honestly believed that going back to the moon was going to be a regular occurrence,” Gutheinz said.

But there were only five more journeys before the last moon landing, Apollo 17, in 1972.

Authentic moon rocks are considered national treasures and cannot legally be sold in the United States, Gutheinz said.

Now a lawyer near Houston, Texas, he’s also a college instructor who’s enlisted the help of his students. They record their findings of the whereabouts of the discovered moon gems in a database.

“The people of the world deserve this,” he said. “They deserve to see something that our astronauts accomplished and be a part it.”