Deep in the woods near Brushy Creek stands an old beech tree, its smooth bark etched with dozens of carvings, including biblical references, a heart and a legless horse.

Bob Brewer was 10 when his great-uncle, W.D. “Grandpa” Ashcraft, pointed it out on a logging trip 57 years ago.

“He said, ‘Boy, you see that tree? That’s a treasure tree,’ ” Brewer recalled on a recent visit to the site. “ ‘You see that writing? If you can figure out what that is, you’ll find some gold.’ ”

The old man didn’t elaborate, but his words stuck with Brewer through childhood and two tours of duty in Vietnam as a Navy helicopter crewman. So did memories of Grandpa’s frequent, unexplained horseback rides into the nearby Ouachita Mountains.

In 1977, after retiring from the Navy, Brewer returned to western Arkansas and took up an obsessive search -- for buried treasure, and for his family’s links to a secretive, subversive Confederate group, the Knights of the Golden Circle, or KGC.

After many years of research, he is among those who believe that the group buried millions in ill-gotten gold across a dozen states, to finance a second Civil War that never came to be. And he thinks Ashcraft and his son, Odis, had something to do with it.

“I think Grandpa Ashcraft and Uncle Ode had a secret,” Brewer says.

A similar theme will play out on the big screen Dec. 21, when Nicolas Cage returns as code-breaking treasure hunter Ben Gates in “National Treasure: Book of Secrets,” a sequel to Disney’s 2004 hit. Brewer is a consultant on the film.

But although Cage’s character searches for Confederate gold and his ancestral ties to the Lincoln assassination, Brewer’s journey shows, once again, that real life can be stranger than fiction -- or at least as intriguing.

Steeped in the history of the South and the West, his quest is haunted by the legend of Jesse James and imbued with the mysterious stuff of Freemasonry, coded treasure maps and conspiracy theories dating to John Wilkes Booth.

Along the way, Brewer says, he has unearthed about $200,000 worth of gold and silver coins. It’s enough to support his modest lifestyle, and to thumb his nose at those who might think he’s just another old coot with a metal detector.

“It’s my damn story,” he says, “and if they don’t believe it I’m not gonna worry about it, damn it. Pardon my French.”

Brewer’s life is detailed in “Shadow of the Sentinel: One Man’s Quest to Find the Hidden Treasure of the Confederacy,” a book he wrote with Warren Getler, a former Wall Street Journal reporter.

The authors say their 2003 book, reissued in paperback as “Rebel Gold,” sheds new light on the hidden history of the KGC, even as it lays out Brewer’s efforts to trace his familial connections to the group and crack the code behind its legendary “depositories.”

Having found smaller coin caches, Brewer says he’s now on to “a big, big one” in Oklahoma -- big enough to more than validate his 30-year search.

“It was supposed to have been $2 million when it was buried,” he says. “We figure it’s about 80 times that face value.”

The hunt that brought Brewer to this point began in earnest after he retired from the Navy in 1977 and started spending time at a Hatfield coffee shop, where talk often turned to treasure-hunting. Some spoke of “Spanish treasure signs,” similar to the markings his great-uncle had shown him.

Spaniard Hernando de Soto had explored the nearby mountains in 1541 and local legend held that he stashed gold there. Over time, Brewer came to doubt the Spanish angle, but linked what his forebears had told him to what he was hearing in town.

He sketched the symbols others described, tracked them down when he could and plotted them on topographical maps. During a stint as a state inspector of beekeepers, he explored remote areas of the forest and found more carvings on trees and rock faces.

Many were recurring symbols: snakes, turtles, crescent moons, crosses, numbers and letters with odd flourishes. Brewer figured they were cryptic indicators of distance and direction, clues to buried riches.

By mapping them, Brewer surmised that they ran along lines that might extend for miles as part of a larger “treasure grid.” Tracing the lines with a metal detector, he says, he learned to systematically find buried clues, one leading to the next, everything from gun barrels to farming implements to milk can lids.

If that sounds far-fetched, it did also to some of the 400 or so residents of Hatfield, including Brewer’s wife, Linda.

“A lot of her friends, and even my own family, were telling her, ‘You better watch Bob because he’s going off the deep end,’ ” Brewer says. “She was beginning to believe it, too.”

But Brewer persisted, and concluded that clues could be found not only in carvings on trees but also in the trees’ shape. Some appeared to have been contorted as saplings, or had oddly grafted limbs that caused them to grow into unusual shapes and directional pointers.

Following a line from one such “hoot owl tree,” Brewer says, he found the carved beech that Grandpa Ashcraft had shown him several decades earlier.

He studied its symbols, “walked the lines” radiating from them and found buried horseshoes and other clues that led to his first cache in 1991 -- a canning jar filled with gold and silver coins from the 1800s, their $400 face value a fraction of their actual worth.

Brewer says he was “stunned” by the find, in the forest about 10 miles from his home.

“I was totally wiped out for a couple of days and couldn’t sleep for a couple of nights,” he says. “I thought I had it all figured out and I’d be rich within a week. I was a little wrong about that.”

The Brewers made a video about the carved beech, dubbed the “Bible Tree” for etchings such as “1st Thess 3:2,” an apparent reference to First Thessalonians. It was a hit at treasure-hunting shows, and Brewer soon was trading stories and information with others who shared his esoteric interest.

In 1993, one of them showed Brewer a book about Jesse James, with passages about the Knights of the Golden Circle, buried Confederate treasure and cryptic symbols.

Founded in the 1850s by George Bickley, a former Virginian living in Cincinnati, the group was reputed to include prominent political figures and Confederate leaders, among them Gen. Albert Pike, a high-ranking member of the Scottish Rite of Freemasonry.

One of the things that led Brewer to link his family to the KGC were “Pike” carvings he’d seen on trees. Another was Grandpa Ashcraft’s mysterious, daylong rides into the woods.

Sometimes his great-uncle told him he’d been hunting “cows,” says Brewer, who only much later learned it might have been short for “cowan,” a Masonic term of contempt for intruders. Grandpa had shown him where one was buried amid the pines and hardwoods.

“He said the man got in here, got to messing around and putting his nose where he shouldn’t have, and got himself killed, " he says.

Eventually, Brewer concluded that Grandpa and Uncle Ode were part of a generations-old network of “sentinels” who watched over caches of KGC money. Much of it came from government-payroll holdups and train robberies, according to Brewer and others who say Jesse James was a leader and benefactor of the group.

Ceci Gillespie thinks some of the loot wound up on a chunk of property she and her sister own in Wapanucka, Okla., about 100 miles southeast of Oklahoma City.

“We’ve had at least 10 people show up with the same idea, that Jesse James buried treasure there,” Gillespie says, starting with an 87-year-old man who greeted her with a “treasure map and his ‘list of reliable facts’ ” some 20 years ago.

In the mid-1990s came Brewer, teamed with an Oklahoma schoolteacher who also had a Jesse James treasure map. In the area, they found a jar of silver coins dated 1812 to 1880, Brewer says, but their hunt was cut short when the sisters booted them from the property.

Brewer says the teacher doubled back without him and found another cache of gold coins. The man might later have struck it even richer, according to a 1995 story in the Daily Oklahoman, which said he’d “unearthed a Wells Fargo safe full of gold coins” at an undisclosed location.

If it was from her property, Gillespie says, she’s never gotten any of it, though she is convinced that millions in gold are still stashed there.

Robert Smith, a University of Oklahoma law professor who has written at length about Jesse James and other American outlaws, dismisses stories of huge treasure troves.

“I know very little about the Knights of the Golden Circle or whether such an organization even existed,” he says. “But my own feeling is this stuff about buried gold, as far as Jesse James is concerned, is nonsense.”

James M. McPherson, a Pulitzer Prize-winning Civil War historian and a professor emeritus at Princeton University, has his own doubts about the group’s reach.

“There certainly was an organization called the Knights of the Golden Circle,” McPherson allows, noting the group sought to spread slavery by annexing territory in Mexico and the Caribbean in the years before the Civil War.

But once the war began, “the story becomes pretty shadowy,” he says.

“My guess is that as the war went on, its reality kind of shaded over into myth,” he says.

Brewer’s co-author Getler, who met Brewer in 1998 and spent five years with him in the field and on a lengthy paper chase, counters that “we dug a lot deeper” into the group than anyone before.

“The Knights of the Golden Circle were a much more powerful organization than history gives credit to,” Getler says.

At the National Archives in Washington, he and Brewer scoured files and rare-book collections, finding the personal prayer book of KGC founder Bickley, who in 1863 was arrested as a spy but never charged, and died in 1867. Inside the book was a hand-written key to the group’s code.

The pair interviewed descendants of members, searched the Library of Congress for relevant writings and pored over the archives of the Pinkerton detective agency, which had pursued James. Their search of an online database yielded illuminating articles from newspapers, magazines and journals dating to the 1800s, and at Georgetown University Library they found works on Booth.

They concluded Booth was either a KGC member or was helped by the group while on the run after shooting President Lincoln at Ford’s Theater on April 14, 1865.

“No one can be sure,” Getler says, “but we are pretty confident that the KGC, the most powerful subversive group that ever existed in the United States, was very involved in the assassination of Lincoln.”

He’s also confident that Brewer is on to something very real.

“This is not crop circles,” he says.

Brewer’s quest has taken him from Arkansas to Georgia to Arizona and back to Oklahoma, where he and two partners have zeroed in on a site more than 100 miles from the Gillespies’ land.

Like other treasure hunters, they are cagey when discussing their work, loath to let slip too many details about exactly where and what they’re doing.

They say the Oklahoma search got held up by summer rains and flooding, which produced four-foot-high grass. It’s crawling with snakes and too high to work in with metal detectors, they say, and hiring someone to mow it would draw too much attention.

Others might be watching and could beat them to the gold. Brewer is willing to wait it out.

“We know where it’s at now,” he says. “All we have to do is put our detectors over it and we’ll find it.”

In some areas, treasure hunting is banned by law or requires permission from private property owners, or state and federal agencies that oversee public lands. At the Oklahoma site, Brewer and his partners have a contract with the owner.

“We don’t ever go anywhere without permission -- period,” says John London, 63, an Amarillo, Texas, electrician and satellite dish installer working with Brewer. “There are no ifs ands or buts about it, and if you don’t get it, the ‘butt’ will be yours.”

Along with metal detectors, global positioning devices and laptop computers with mapping software, London’s treasure-hunting tools include dowsing wands and an “information rod” made from an old rabbit-ears TV antenna with a silver dollar riveted onto it.

He insists it works, but says he hasn’t had to rely on it in Oklahoma.

“This is pure KGC research that has brought this stuff up,” he says.

Another partner, Jim Weaver, a 63-year-old window and siding salesman from Hutchinson, Kan., credits Brewer’s “unique ability” to decipher symbols and find clues.

“You can say it’s a gift. You can say it’s genetic,” Weaver says. “I don’t know what it is, but Bob really has discovered something remarkable.”

He says he’s seen evidence “beyond any possible shadow of a doubt” in Oklahoma.

“If we bring this thing to the conclusion we anticipate,” he says, “it will be mind-boggling.”

If he does hit it big, Brewer says, it won’t change his life much. He has all he needs: a good family, enough money to pay his bills, a nice house on a patch of land where he can step out his front door and shoot deer and wild turkey all day long.

Mostly, he just wants to finish his life’s work.

“Sometimes I wish I had never started it,” he says. “But I was always good at puzzles and when I set my mind to doing something, I do it.”

kim.christensen@latimes.com