With the coiled energy of a stalking cat, Ray Stanford splashes outof the stream and onto a rocky sandbar, his knee-high, hunter-green boots leaving shallow heel prints that fill with water and begin to melt. Crouched, Stanford scans, head down, wavy silver hair dappled in the sunshine. Birds tweet. Water rustles. It’s 3:30 p.m.; the sun is at mid-angle, throwing good shadows. Stanford picks up a flat slice of pale yellow rock, a rough triangle the size of his hand. He rubs it with his thumb, tilts it this way and that.

“You see that?” he asks. A splayed mark etches the rock’s surface. “It looks like a little three-toed dinosaur was here.”

Stanford and I have been splashing around for all of two minutes. Already, the dinosaur king of College Park has scored.

A few minutes later, Stanford picks up a bigger slice of brown rock. He thumbs mud out of an impression the length of his index finger. “I can guarantee that’s a toe,” he says. The mark is smeared, indistinct. I’m not sure I believe him.

But Stanford has a special visual talent. He sees things other people don’t.

A week later, Stanford e-mails. After further inspection, he has decided that this seemingly unspectacular find is “a WONDERFUL specimen of a running, turning-left-at-high-speed dromeosaurid footprint.”

Popularly known as velociraptors — and made famous by “Jurassic Park” — these little dromeosaurids darted about on two feet, arms tucked, slender tails bobbing.

Here, in the desultory woods behind a Prince George’s County high school, along a creek bed littered with dented Coors Light cans and bent cafeteria spoons and spent Doritos bags, one of these knee-high speedsters hung a quick left 112 million years ago, during the early Cretaceous era.

It was fleeing a snapping carnivore! It was chasing a fish! Or maybe it was just out for a run.

Stanford’s imagination fills in the blanks. It’s what he does.

***

Wiry, voluble, energetic 73-year-old Ray Stanford could almost pass for a paleontologist. But his hair is a little too short, his beard too trim, his button-down shirt too tucked. And he talks too fast. This Texan is an amateur, although he disdains that term. He’s self-taught, a gentleman naturalist.

And now he’s leading me to the Stanford Museum: his living room. Worried about thieves, Stanford asks me not to disclose the location of the rambling, white, three-story farmhouse, circa 1870, that he shares with his wife, Sheila, who works as an information specialist at NASA’s Goddard Space Flight Center in Greenbelt.

In we go, through a dim foyer.

Boom! It’s like a rock quarry exploded, threw up a great whirling cyclone of stone — flat pieces, round ones, some smaller than a coaster, some bigger than a dinner plate, smooth pieces and jagged ones, triangles, rectangles, crazy irregular shapes, dun, gray, tan, ochre, charcoal, splashes of purple and streaks of yellow — and deposited the whole shebang into a great flowing river of rock.

The river bears left from the door, growing higher, overtaking a wooden chair, then up onto the radiator and back behind a big easy chair, sloping into a rampart against the wall, reaching up almost to the window, then across a bookcase and over a floor-standing speaker and further, up onto a shelf, heading for the ceiling in the far corner.

There is more. A door opens to the kitchen, where the great rock river rolls on, over a table, jumping onto the stove, into a back room, out the back door and down three steps, petering out — finally — with a few big slabs on the ground.

And footprints! Imprinted upon every rock — each piece, each slab, each slice, all of them, every last one, hundreds and hundreds of rocks, maybe a thousand — is a dinosaur track, or three, or 12, from three-toed scratch marks smaller than a penny to elephantine ovals size 18EEE.

This is College Park? More like Cretaceous Park.

“My jaw stayed dropped for an hour,” said Robert T. Bakker, perhaps the most famous dinosaur hunter of the past half-century, who toured the Stanford Museum some years back.

Here and there, riding the rocky waves, peek out actual dinosaurs — the plastic variety. A leering two-legged carnivore threatens from behind a chair, all stubby arms and flashing teeth. Under the coffee table, a little low-slung, spiky ankylosaur stands guard. Each dinosaur is roughly of the type that made the track upon which it stands: visual aids for the overwhelmed visitor.

There’s even more to take in, as Stanford’s interests range far beyond dinosaur tracks. Cases of Indian arrowheads hang on the walls. Dozens of matchbox-size plastic boxes hold slices of meteorites. A dozen stone discs cover a round coffee table, some resembling old-style flying saucers, pieces for a game known as Chunkey played by the plains Indians beginning 1,500 years ago. The Indians rolled the discs and threw spears at them.

“Take a seat,” says Stanford, his turquoise bolo tie swinging as he settles on the easy chair. “There’s a lot to show.”

***

The first time Ray Stanford spotted a dinosaur track — in a rivulet in Riverdale — he left it behind. There weren’t supposed to be dinosaur footprints here. Unlike the West, where vast tracts of exposed bedrock draw dinosaur hunters, Maryland is covered by forests, freeways and suburbs.

In fact, before Stanford, only a handful of dinosaur tracks had ever been found in Maryland, in much older rocks 100 miles away in a quarry near Emmitsburg. Some of the great dinosaur hunters of the 19th and 20th centuries, including Yale University’s O.C. Marsh, had searched the Washington area and found the bones and teeth of three or four species. But no footprints had ever been found. The iron-rich geology wasn’t right for it. The textbooks said so.

Stanford knew this. In 1994, his three children from a previous marriage were visiting, and his youngest son, then 9, was going through his dinosaur-crazy phase.

One August afternoon, out hunting for Indian arrowheads, Stanford found a flat rock with an impression that looked like three fat toes. The children had been flipping through an illustrated guide to dinosaur tracks, so they were primed: It was the footprint of an iguanodon, a two-legged herbivore.

Stanford thought that unlikely and dropped the piece. But he returned a few days later, finding a similar-looking piece, with three splayed impressions. He kept it.

On his third trip, another discovery set him “on fire”: two wider, rounder footprints. The claw marks, the rounded shape, the girth: Stanford put it together. A young sauropod — a long-necked tree grazer — had stamped them.

“If a sauropod can run, this guy was running!” Stanford says. “I got more and more excited. I was like a kid.”

Tromping through streambeds, flipping rocks, he learned what to look for. Within a year, he and Sheila had collected 90 pieces with nearly 20 types of tracks.

No dinosaur footprints in Maryland? There were stampedes of them.

***

Taking notes at the Stanford Museum is like chasing a race car on a bicycle. For four hours, Ray talks nearly nonstop, flashing footprint after footprint.

He ushers me to Pterosaur Corner, where he has stacked the tracks of flying reptiles with crested, narrow heads. (Pterosaurs are popularly known as pterodactyls.)

“What I’m going to show you will reset the clock on size evolution of pterosaurs,” he says.

Before Ray Stanford, no one had found a pterosaur footprint east of the Mississippi River.

He has a pile of them.

The slab he points to is one of his bigger pieces, 18 inches long. It holds a huge three-digit handprint, each slender impression tapering to a pointy claw mark.

“Just look at that digit length,” says Stanford.

Pterosaurs had three fingers dangling from the middle of each wing; when the animals landed, they left widely splayed marks.

“This thing was humongous,” Stanford says: 400 pounds with a wingspan of 40 feet, a dive-bombing Learjet with serrated teeth. On the ground, these creatures balanced on their wingtips, eerily, like vampire bats taller than a house.

The current pterosaur size champion, Quetzalcoatlus northropi , hailed from Texas and had wingspans approaching 38 feet. But it lived 50 million years after whatever made this monster print. (All of the tracks Stanford finds come from rocks that are about 50 million years older than the ones in Texas.)

The biggest flying beast ever, millions of years before its time, soaring over prehistoric Maryland?

I was skeptical. So I called one of the world’s foremost dinosaur trackers, Martin Lockley, who is recently retired from the University of Colorado in Denver. He toured the Stanford Museum in 1999 after appearing on the Diane Rehm radio show and getting a call from Stanford.

“It is equal to the largest, or is possibly the largest, pterosaur track in the world,” Lockley said. He is eager to co-author a scientific paper on it with Stanford.

But Stanford doesn’t know when he’ll get around to writing it up.

We move on — so much to see! — to the other end of the size scale. Stanford pulls out a plastic case the size of a credit card, opens it to display five small chips of stone. Three-toed footprints improbably scratch the chips; each could fit on a penny.

The tiniest dinosaur footprints ever found, says Stanford.

They were made by a chick-size hatchling of a new-to-science species of plant-eating dinosaur that Stanford dubbed Hypsiloichnus marylandicus. “Dinosaurs had babies, too,” he says.

Curiosities abound at the Stanford Museum, such as chunks of fossilized dinosaur feces, or coprolites. There’s a dark ice-cream-scoop-shaped chunk; a ruddy, knobby 98-pounder; a smaller one with a splayed-toe track (“He stepped where his mother told him never to step,” Stanford says. “I always tell that to the Cub Scouts.”).

The collection could launch a dozen academic careers, keep an army of graduate students toiling for decades. But Stanford doesn’t play by those rules. He doesn’t have to publish or perish.

Instead, he sits in his easy chair and ponders each find, turning it over in his hand and his mind.

He sells nothing, despite offers. “Oh, God, no,” he says.

Robert Weems, a fossil hunter with the U.S. Geological Survey in Virginia and among the first professionals to view the Stanford Museum, recalls worrying that he was driving out to “look at some squiggles on a rock.”

Instead, he found a modern-day Edward Hitchcock, the geologist and Amherst College president who collected 20,000 dinosaur tracks from the Connecticut River Valley starting in 1836 before the word “dinosaur” had even been coined.

Stanford sees his collection “as his scientific legacy,” says Weems. “If he had another personality, it would be on eBay and we wouldn’t know about it.”

***

Before Stanford’s haul, the remains of just three or four species of dinosaurs were known in Maryland. He has added at least 14 types of dinosaurs and winged reptiles, and, just possibly, a stunningly large early mammal. And in 1998, he discovered a fossilized baby dinosaur, an armored browser known as a nodosaur. It’s the only hatchling nodosaur found anywhere, and one of the only known hatchling dinosaurs of any kind, two points Stanford eagerly makes.

It now sits under lights, in the “Dinosaurs in Our Backyard” exhibit in the Smithsonian’s National Museum of Natural History.

“Ray has footprints of dinosaurs we don’t have bones for yet,” said Matthew Carrano, curator of dinosauria at the Smithsonian Institution. “We learned more about these animals than we had in 150 years.”

These creatures thundered, skittered and flapped their way across an ancient floodplain that later hardened into a geologic formation known as the Arundel Clay. This 112-million-year-old spine of bedrock runs from the southern tip of New Jersey to Baltimore, then through Prince George’s County and into Virginia.

Stanford finds the pieces as “float.” After heavy rains, fast water scours the bottoms and banks of streams, breaking up the substrate. Some of this geological wreckage gets hung up on sandbars and shorelines, where Stanford spots it. I ask Stanford how he has spotted so many dinosaur tracks where no one ever had before. He allows that he possesses an unusual ability to recognize visual patterns, but couldn’t be more specific.

Stanford’s tale would be familiar to historians of science: He is the uncredentialed enthusiast, who, oblivious to the boundaries that the high priests of a given field have staked out, naively stumbles outside those lines and into a great discovery.

“He’s John the Baptist of Cretaceous fossil footprints. He’s a national treasure,” says Bakker, Steven Spielberg’s dinosaur guy, whose bushy visage and wide-brimmed hat appear regularly on Discovery Channel. “He’s of the great tradition of the self-taught amateur who keeps on hunting for fossils despite rain and wind and official discouragement.”

Oh, yes, that: official discouragement.

Early in his dinosaur-collecting days, a prominent local dinosaur hunter hounded Stanford,spread rumors that he had hauled in the footprints from out of state. The first time Stanford presented a track at a dinosaur enthusiast meeting, in 1998, a prominent German dinosaur tracker, Adolf Seilacher, stood and publicly disputed Stanford’s interpretation of the find and challenged that it came from Maryland.

But by now, some 40 top academic paleontologists and ichnologists (track specialists) have toured the Stanford Museum and proclaimed its authenticity.

Stanford has co-authored three scientific journal articles. Inside the textbook “Dinosaurs of the East Coast,” author David Weishampel of Johns Hopkins University wrote in black marker: “Now that I’ve met you, this book is in for a big rewrite.”

For Ray Stanford, none of that is enough.

***

Saving the footprints — and his reputation — will always be an urgent rescue operation, a scientific Saigon.

“I can’t quit,” he says. “Who else will do this?” In 2004, a near-fatal heart attack stole 15 percent of Stanford’s heart. “I have to dedicate whatever I’ve got left to doing this.”

The three tons of rock in his house will need to go somewhere else eventually. “People keep telling me I should give it to the Smithsonian,” he says.

There are other suitors, chief among them Lockley’s Dinosaur Tracks Museum in Boulder, Colo.

In 2004 and 2007, Lockley, Weems and Stanford finally put the collection in the scientific record, publishing two overviews of 300 of the tracks in the journal Ichnos.

So, esteemed Dr. Lockley, what should Stanford do with his collection?

“He’s understandably — I won’t say he’s possessive — but he wants to keep it all together and ruminate on it,” Lockley says. “I’m sure he agrees that in the long run it should go to a proper institution. I would hope it would be us.”

***

On Saturday, Dec. 1, 2007, Stanford went dinosaur tracking; recent rains had raised his hopes for new float. He gathered his plastic bags and drove to the high school. It was senior picture day. Forty degrees and bright. Cloudless.

As Stanford crossed the parking lot, he looked up. And there, beyond two rows of parked cars, above the two-story brick building, he made the day’s first discovery.

It was a shuttlecraft docking to a mothership. Stanford snapped three pictures of it.

***

This is where the story takes a sharp left turn. I’m back at the Stanford Museum, up in Stanford’s second-floor office. It’s musty, the shades are drawn. Small dinosaur teeth, slices of meteorites and sparkly minerals, back issues of Science News and Archaeology magazine cover every surface. A dusty, gray E.T. the Extraterrestrial alarm clock presides from atop a cabinet. “UFO Landing Area,” reads a small green sign on a shelf.

Now we arrive at Stanford’s original obsession, the one that stretches back to his childhood. Long before the first dinosaur track hopped into his life, Ray Stanford chased UFOs, a term he professes to dislike. “It’s so loaded,” he says. He prefers “anomalous aerial objects,” or AAOs.

“I’d rather track AAOs than dinosaurs any day,” he says. “That’s my streambed in the sky.”

On his computer, Stanford is showing me one of the pictures from that day in 2007. “Just look at that!” he exclaims. “It was moving up, and then zoom.”

Two white smudges appear to hover over the school. Or maybe it’s one T-shaped smudge. The horizontal smudge is tube-like but blobby, like a sausage losing its filling. Beneath it, a smaller, fuzzy white vertical object noses the tube. That, Stanford says, is the shuttlecraft coming in to dock.

This is not the Battlestar Galactica.

Still, it’s a hint of something. Could be a cloud, except I’ve never seen one that shape. Besides, the rest of the sky is blue, and weather records confirm it was a clear day.

It is only now, here, after half-day tours of the Stanford Museum and trips to the creek, after months of e-mails and phone calls, that Ray Stanford reveals to me his life’s purpose. The dinosaurs? Well, sure, Ray Stanford just happened to blow open a wormhole 112 million years deep into a hitherto unseen era of fantastic beasts roaming the Earth. Yeah, he did that. But that’s small stuff. This, the secret of these craft, how they move, who they carry, the occupants — that’s what keeps Ray Stanford up until 4 a.m.

The first sighting he reported, in 1954 in Corpus Christi, where he grew up, made Fate magazine. A framed cover of the May 1956 issue hangs on his office wall: It's a dramatic illustration of an outsize flying saucer, glowing white, with three trench-coated police officers standing beneath it looking up. TEXAS SAUCER CONTACT, blares the cover line. POLICE AFFIDAVITS!

“You can imagine when this came in the mail,” Stanford says. “What a thrill.”

He details the encounter for half an hour. He admits that the cover drawing is a gross exaggeration; the saucer was neither that large nor that bright.

At key points in the story, Stanford rolls up his right sleeve and sticks out his arm. “I’ve got goose bumps, my arm hair is standing up!” I lean in to look. He does; it is.

Ray and his identical twin brother, Rex, came of age when UFOs were booming. The first wave of sightings occurred in 1947, when Ray was 9. At 15, in 1953, Ray devoured George Adamski’s pulpy alien-contact tract, “Flying Saucers Have Landed,” and began corresponding with Adamski.

Later, a photo Adamski took of a flying saucer was revealed as a cheap hoax, a metal lid with light bulbs as landing gear. Ray still stings from that deceit. He spits out Adamski’s name like a hard seed.

Ray built rockets and won first prize in the 1955 Texas state physics competition. Despite obvious talent, he never managed college. Instead, he moved to Austin and became a psychic. Whoever came up with the slogan “Keep Austin Weird” may have had Ray Stanford in mind.

Starting in 1961, he made his living leading a group of paranormal explorers called the Association for the Understanding of Man. He charged $35 for psychic readings, and the group sold recordings and transcripts of Stanford’s readings, in which he made contact with veiled entities who offered their opinion on the Fatima miracle, the nature of Christ, or whether the readee had a dread disease. Rex, meanwhile, became a professor of psychology at St. John’s University in New York, where he studied ESP, among other things.

Two big donors — an Austin real estate mogul and a Texas oilman — helped launch Ray Stanford’s next venture in the early 1970s, the one that catapulted him to middling media glory: Project Starlight International.

Donning white jumpsuits and green goggles, Stanford and his merry band of alien hunters built a landing pad in the hills west of Austin. It was ringed with spotlights that flashed odd rhythms. A chunky device shot a laser into the sky that transmitted, via pulses, messages of peace. It was totally disco.

Stanford would wave at the sky and shout, “LAND OVER HERE. WE HAVE NO WEAPONS.”

Big VHS video cameras, magnetometers and gravitometers were at the ready to document any fly-bys or landings.

This was a time in America when UFOs made the nightly news. Saucers over Phoenix. Cigars buzzing Buffalo. A streaking flash in Utah. The late 1960s to the late 1970s saw a fevered peak of the UFO craze, and Ray Stanford was smack in the middle of it. No, he never became as famous as Barney and Betty Hill, whose alien abduction story launched a Hollywood-mytho­logical-industrial complex that climaxed during the nine-year run of “The X-Files.” But he worked the media and clawed at the center of the fray.

He made the Phil Donahue show.

He chased a lot of UFOs. Er, AAOs. He documented it all. And he’s showing me everything. For seven hours, Ray Stanford reels through 437 PowerPoint slides. That’s Part 1.

Deltoids. Shuttlecraft. Saucers. Motherships. Beam-ahead propulsion. Time-shifting. Dimensional leaps. Military men. NASA labs, coverups, a green glass globe on the moon.

It would take Fox Mulder another decade to chase it all down.

Toward the end — it’s nearly 6 p.m.! — I’m feeling faint from lack of food and drink. Reverting to his less preferred term, Stanford says, “This is as good evidence you’ll see for UFOs anywhere.”

I want to believe. I do.

“The universe is so damn strange.”

“The aliens, are they trying to create religion?”

“I’m not saying this is true, but maybe we’re just something for them to play with.”

“It may be a tourist operation? This could be Disneyland for them!”

Ray Stanford more than believes. He has invested his life in documenting UFOs. And perhaps, I think, just maybe, his wildest notions lie a nanometer inside the realm of possibility. A city in space, green globes on the moon, astronauts conversing with aliens — much of it is easy to debunk. But who am I to say that time-stopping, dimension-hopping aliens do not exist? A negative cannot be proven.

And that, of course, is the crux of why the alien hypothesis will never die. There’s no way to exclude all possibility. Anything can and might happen. An enormous pterosaur may have landed in your backyard 112 million years ago and you — you — dig up the handprint! I mean, what are the chances?

So the aliens live on, in Stanford’s mind, and on his computer, and who knows, maybe up there, too.

***

Iam back in Stanford’s office.

Again, I ask him why he thinks he sees the AAOs and the footprints.

He tells me a story from his childhood. When he was 6 or 7, a big redheaded 9-year-old smacked him on the head. “Rattlebrain!” Stanford shouts, tearing up. “I had this rattlebrain for at least three years.”

The blow rewired his brain, he tells me, turning him into a “walking, talking detector.”

I am in no position to disagree.

Stung by criticism of his UFO hunting, Stanford keeps that part of his life out of view of some of his dinosaur collaborators. Bakker, for one, didn’t know about Stanford’s past. “It’s more of a religion” than a science, Bakker said of UFO hunting in general.

“You can wound him deeply by saying he’s a crackpot,” says John Young, 40, a computer programmer whose father was a member of Project Starlight. As a 5- and 6-year-old, Young ran around the UFO landing pad, enthralled by the light show. “Lots of people give Ray a hard time, but he’s the real deal — a maverick, an eccentric gentleman, just a supercool guy. He is 100 percent what-you-see-is-what-you-get. He’s a genuine dude. He is doing it because he wants to learn the truth, not to sell copies of the DVD. There is no DVD. He’s just that way.”

Young pauses, dramatically: “He’s a searcher.”

I think about that. Like all of life’s profundities, the lesson Ray Stanford has to offer the world may be a simple one: Keep your eyes open. Keep looking. A hidden world, a universe trapped in time, a realm so foreign and bizarre as to stretch all credulity, may be lurking just beneath your feet — or, maybe, just maybe, winging over your head.

Brian Vastag is a Post science reporter. To comment on this article, send e-mail to wpletters@washpost.com.