When Neil Armstrong trained at the Nevada Test Site, no one paid much attention to his footprints.
Back in February 1965, Armstrong was just another hotshot pilot turned earthbound astronaut. It would be another year before his first spaceflight on Gemini 8 and almost four years until he drew the assignment of his life as commander of Apollo 11.
Armstrong and 12 other astronauts spent two days at the test site as part of a crash course in geology.
"They were essentially being taught what to look for" on the moon, said aerospace historian Peter Merlin. "These guys were test pilots. You didn't get an actual geologist until the last mission (Apollo 17) with Harrison Schmitt."
And with tight limits on how much weight their spacecraft could carry, the astronauts had to be choosy.
After its historic moon landing, 40 years ago Monday, Apollo 11 returned to Earth with less than 50 pounds of moon rocks.
Eight of the 13 astronauts who took part in that first field trip at the test site in 1965 would eventually travel to the moon, among them Edwin "Buzz" Aldrin and Michael Collins, Armstrong's Apollo 11 crewmates.
All three Apollo 11 astronauts had been to Nevada before.
Collins completed advanced fighter jet training at Nellis Air Force Base in the early 1950s.
Aldrin spent about a year as a Nellis gunnery instructor after flying combat missions in Korea.
He joined NASA in 1963 and returned to Nevada in 1964 for three days of desert survival training with Collins and 12 other astronauts in a remote area outside of Reno.
Armstrong made an unscheduled stop in central Nevada on April 24, 1962, when he got his T-33 trainer stuck in the mud during a "touch-and-go" maneuver on a dry lake bed in Lander County.
Riding in the back seat of Armstrong's jet that day: Chuck Yeager, the first pilot to break the sound barrier.
The Apollo 11 crew's only astronaut training in Nevada came during that two-day trip to the test site in 1965, but the federal installation about 65 miles northwest of Las Vegas played a larger role in later moon missions.
Starting in September 1970, NASA conducted seven more training sessions in and around the test site.
Most of the exercises focused on two craters left over from the "Schooner" and "Sedan" underground nuclear tests, which Merlin said provided a "virtual lunar landscape," albeit one covered in sagebrush.
"That was as close an approximation to the craters of the moon as you can get," said Troy Wade, chairman of the Nevada Test Site Historical Foundation, which operates the Atomic Testing Museum.
Dressed in blue jeans, cowboy hats and bulky, white backpacks like the ones they would wear on the moon, the astronauts practiced geologic survey work and learned to recognize unusual and important rocks.
They also tried out some of the tools they would need to gather samples.
"The suits did not lend themselves to bending over," said Merlin, who works as a private contractor at NASA's Dryden Flight Research Center at Edwards Air Force Base, Calif.
Nevada's craters, both the manmade ones on the test site and a few volcanic ones in northern Nye County, also proved useful for testing NASA's new wheels.
Before the final two Apollo flights, astronauts tooled around the Nevada desert in a lunar rover training vehicle conducting practice survey missions.
Merlin said the rover performed very differently on the moon, where the force of gravity is only a fraction of what it is on Earth.
"It was really quite a ride," he said. "They got some pretty good dune-buggy action out of that thing."
The last astronaut training session in Nevada took place over two days in early September 1972, three months before the final Apollo mission began.
Of 12 men who walked on the moon, 11 trained in the Silver State. And although their work here represented only a small fraction of their overall training, it made an impression on them.
In transmissions from the moon, the geologist-astronaut Schmitt compared a crater he saw there to the "Little Dan" crater astronauts explored, and named, at the Nevada Test Site.
As NASA prepares for future trips to the moon and beyond, some predict astronauts might one day return to Nevada to train.
After all, there is no shortage of testing and training to be done.
As Merlin put it, NASA is basically "starting from scratch" four decades after the first successful moon landing.
No field or training exercises are planned in Nevada, but the state contains a number of areas suitable for tests under extreme conditions, said Ashley Edwards, spokeswoman for the agency's Exploration Systems Mission Directorate.
"A team of NASA officials went out to the Nevada site in November 2007 to perform a site survey for locations to do tests with the Lunar Electric Rover," Edwards said. "The site ranked high but was ultimately not selected."
Contact reporter Henry Brean at hbrean @reviewjournal.com or 702-383-0350.