(AirforceTimes.com) - It didn't take long for the lady in gray to show up in the boys' room shortly after the Keen family arrived at their new duty station in Hawaii.
It was the winter of 2009. Maj. Jake Keen, his wife Carrie and their two boys had just moved into their new house on Kline Road, lined with palm trees and typical military-issue units on the northeastern edge of the Army's Schofield Barracks on Oahu.
The mysterious woman first appeared before their youngest son in the middle of the night.
"He was just 3 at the time and had a very active imagination, so I didn't think much of it at first," Carrie Keen says.
Then the older brother started seeing her. Eventually, her husband started seeing the apparition, too.
"I never physically saw her, but she would definitely let me know she was there. She was very active. We think she had been a maid," says Keen, who says the presence - whatever it was - lived with them through the entire three years they were stationed in Hawaii.
"It got to the point where my husband would close his eyes when he got up to go to the bathroom in the middle of the night because he kept seeing her," she says. "It was a little freaky at first, but she was never threatening. The boys loved her."
Later, Keen met another spouse who had lived in the same house. Keen probed delicately, asking whether the prior occupant had ever noticed anything strange.
"Oh, you want to talk about the ghost!?" came the quick reply, describing to a T the lady in gray.
Hauntings on the military's bases, boats and battlefields are not unusual, says two-time Iraq veteran and Army Reserve Maj. Dave Goodwin. A full-time St. Louis policeman and part-time paranormal investigator,
Goodwin has spent more than 20 years tracking ghost stories on current and former military installations and battlefields across the country.
"It makes sense that there would be a lot of activity in these military places," he says, because any time you have intense emotions, violence and dramatic periods of history, they leave something behind."
Although he describes himself as a skeptic - most "sightings," he says, are the result of overactive imaginations or hoaxes - he's convinced something decidedly otherworldly is occurring in many of these places.
Author of the just-published "Soldiers and the Supernatural," Goodwin says haunted military installations are great places to visit, whether you see a ghost or not.
"These are places dripping in history," he says. "There's usually so much to see and learn. The possibility of meeting a ghost is just an added benefit."
Some of our favorite haunted military places:
1. Plattsburgh Air Force Base, N.Y.
Although the last military units left this base in 1995, "there's a lot of very eerie stuff around here," says Matthew Boire.
He should know. As owner of the Greater Adirondack Ghost & Tour Company, he sees it just about every night.
An eternally grieving mother is said to search for the grave of her lost child in the military cemetery that dates to upstate New York's frontier days. But it's the Old Stone Barracks where the ghosts of Plattsburgh Air Force Base are "most active," Boire says.
The building, built in 1838 as part of the original Army outpost, is said to have seen several suicides over its long history.
"It's been boarded up since the mid-'60s, but, as I always tell folks on our tours, just because no one lives there doesn't mean that there isn't anyone home," Boire says. "Shadowy figures dressed in period clothing have been seen promenading along the porches only to disappear through one of the many boarded-up entryways."
2. Gettysburg, Pa.
During a late-night lull in the three-day Battle of Gettysburg 150 years ago, Union artilleryman 1st Lt. Benjamin F. Rittenhouse described a frightening scene.
"It was bright moonlight, but seemed to me there were spirits flitting from Little Round Top to Devil's Den and back, all night," he wrote in his dairy. "The only sounds I could hear were the groans of the wounded lying between the lines."
The ghosts of Gettysburg have been roaming the rocky hills, rolling farm fields and foggy roads ever since.
"Battles are the perfect storm for creating ghosts," says Mark Nesbitt, a former park ranger and author of 12 books on the ghosts of Gettysburg and other Civil War battlefields.
With 8,000 soldiers cut down over those three days - and more than 50,000 seriously wounded and missing - maybe it's no surprise that Gettysburg "may very well be, acre for acre, the most haunted place in America," says Nesbitt, who now runs one of the largest guided ghost tours in Gettysburg.
Among some of the most notorious sites for spotting phantom soldiers: Gettysburg College and, of course, Devil's Den, a boulder-strewn section of the battlefield that so spooked Rittenhouse all those years ago.
3. Little Bighorn, Mont.
Over two summer days in 1876, more than 260 soldiers and scouts led by Lt. Col. George A. Custer died fighting thousands of Lakota and Cheyenne warriors across the tall bluffs and deep ravines of southern Montana.
In what became known as the Battle of Little Bighorn, and more widely as Custer's Last Stand, the 7th Cavalry troopers died grisly deaths at the hands of their opponents.
The battlefield is now a national monument, and nearby Custer National Cemetery is the final resting place of 5,000 veterans and their family members.
"If there was ever a place where ghosts might roam, then Custer Battlefield is such a place," says Rob Recce, who has collected scores of stories of hauntings as president of Friends of the Little Bighorn Battlefield.
"The encounters are numerous, and the superstitions go way back," he writes on the group's website, quoting park rangers and battlefield volunteers that "I have known for years and highly respect."
Ethereal Native ghost riders have been seen charging along the bluffs. Several visitors claim witnessing the battle itself as if transported in time.
A building known as the "Stone House," built in 1894 as a residence for the park superintendent and now a library, is particularly active.
Lights turn on and off by themselves, and unexplained footsteps are heard on the second story. The apparition of a woman has been seen coming down the stairs, and one park ranger swears he saw the shadowy head and torso of a cavalry soldier disappear into another room, among other sightings.
4. Fort Leavenworth, Kan.
With nearly three dozen no-kidding "documented" haunted houses throughout this historic Army installation, it's no wonder Fort Leavenworth is dubbed by some as the most haunted active-duty installation in the Army.
"I have three binders full of stories of hauntings around post," says Carrie Keen, the prior inhabitant of the Schofield Barracks haunted house and now chairwoman of the Frontier Army Museum's Haunted Fort Leavenworth Tour.
More continue to surface regularly - and not just old Halloween-inspired folklore stories.
"Many of them are current hauntings," Keen said. "I just got another report today from a family that just moved into a building we call the Rookery who say their housing unit is very active."
Previous residents of the Rookery have reported seeing the phantom of a lady in a long white dress with long gray hair who screams at anyone who comes close. Believed to be the wife of a cavalry soldier who was away on a campaign, legend has it she was tortured and killed during an Indian attack.
She says reports are so widespread that the museum is redesigning its annual tour to weave in more of the stories.
Of course, the creepy remains of the Old Disciplinary Barracks are a natural spot for the supernatural.
While most of the "Castle," as the old military penitentiary is known, was razed about 10 years ago, one of the remaining guardhouses dubbed simply Tower 8 is well known for its ghostly apparitions. A soldier committed suicide inside the tower and, though long since closed, officials say the guard control room sometimes gets mysterious calls from the abandoned outpost.
5. F.E. Warren Air Force Base, Wyo.
If you spend the night at F.E. Warren Air Force Base's FamCamp, don't be surprised to hear otherworldly screams coming from a nearby ravine.
According to base historians, cavalry troops raped and murdered a young Indian woman in the 1920s along the banks of White Crow Creek near the current base campgrounds.
It's just one of the many ghost stories you're likely to hear on the October haunted trolley tours organized by the Paranormal Hunter Observation Group in neighboring Cheyenne.
Before becoming Warren's security force headquarters, Building 34 served as the base hospital, widely considered one of the most haunted spots on the installation.
A phantom nurse is often seen making her rounds through the building. According to base legend, she's one of six nurses killed by a murderous mental patient who escaped from the hospital.
6. The Alamo, San Antonio
"Remember the Alamo" became the legendary battle cry for the fledgling Republic of Texas - and even in the afterlife, it appears many cannot forget that battle.
Indeed, the Alamo, site of James Bowie and Davy Crockett's last stand, where nearly 200 defenders were slaughtered by the Mexican army after a 13-day siege, is considered second only to Gettysburg among military history's most haunted sites, says ghost hunter Goodwin.
"It has all this huge emotion and history, and a lot of that is still bottled up there," Goodwin says.
Ghost stories began emerging within weeks of the battle. First there were the six ghostly monks who suddenly materialized to protect the fort's chapel when Mexican troops were ordered to tear it down.
Then there's the story of buried treasure under the Alamo and the ghosts who guard it.
Goodwin has documented recurring stories of a phantom sentry who frantically patrols the top of the Alamo. Some think he's trying to escape the coming massacre.
Meanwhile, many witnesses have reported seeing freakish forms emanating from the walls of the Alamo itself, sometimes with the sound of fighting and screams.
A ghostly little boy - only visible from the waist up or peering down from a high window - is another common sighting.
7. Fort Monroe, Va.
Before becoming a celebrated author of murder and the macabre, Edgar Allen Poe served as an artilleryman at Fort Monroe, a coastal defense outpost protecting Norfolk. It's said that he wrote "The Cask of Amontillado," his bone-chilling tale of murderous masonry, while stationed there.
Now he's just one of a slew of celebrity ghosts believed to roam the stronghold's ramparts, says Goodwin, the Army Reserve major and military ghost expert.
Both Abraham Lincoln and his Confederate counterpart Jefferson Davis, who was imprisoned at Fort Monroe after Lincoln's assassination, are among them, as well as Ulysses S. Grant and Chief Black Hawk.
"Lincoln is one of those ghosts that seems to be everywhere," Goodwin says. "I don't know how one ghost can get around so much. He must get frequent flier miles or something."
At Old Quarters No. 1, Lincoln's favorite haunt at Fort Monroe, paranormal investigators also have recorded the disembodied voice of a little girl calling for her cat named Greta in the same area where office workers report seeing snatches of a phantom gray cat.
Matthews Lane, which runs along the stronghold's southwestern walls, is better known as Ghost Alley and is said to be haunted by the wife of Civil War Army Capt. Willhelm Kirtz.
She fell in love with another soldier, and Kirtz killed her when he caught them in bed together. Now she roams the alley in search of her lost love.
8. Vancouver Barracks, Wash.
Archaeologist and retired Army Reserve historian Maj. Jeff Davis grew up around the Army's Vancouver Barracks when his dad was a soldier.
With the original fort there dating to the early 1800s, the Army maintained a small presence there until last year.
Davis, author of "A Haunted Tour Guide to the Pacific Northwest" and several other paranormal books on the area, says the barracks is one of the most haunted military installations in the region.
Building 674 in particular is the source of many stories.
"There are dark spirits that may have come from the time when this building was the post hospital," he writes on his website Ghosts and Critters. "There have been several different manifestations. Mike Lakey, a civilian employee, talked of the frustrations he and others had in keeping the front door locked. Several times he would lock the building at night. In the morning he would find the door unlocked. He put tape on the door to see if anyone had opened it during the night and broke the tape. Each time, the door was unlocked and the tape was unbroken. The person who unlocked the door did not go inside, and nobody left."
Mysterious figures have been seen moving through another building known as the Howard House, once the base commander's residence and now a visitor's center. Security devices have picked up strange movements in the 134-year-old house, as well.
"There have been several evening incidents when the alarm detected someone appearing in one of the second-story rooms, in the front of the building," according to Davis. "The intruder was monitored as they walked around the room and then headed out into the hallway and down to a room overlooking the main post parking lot. The intruder remained there for several minutes and then walked back into the first room and then disappeared again."
9. USS Hornet, Alameda, Calif.
Described by some as the most haunted ship in the Navy, purported ghost sightings on this World War II-era aircraft carrier are numerous.
From suicides to freak accidents, some 300 sailors lost their lives aboard the warship over its 27 years of service. And many are said to linger.
Disembodied voices, uniformed sailors appearing and disappearing, and radios and other equipment turning on and off are some of the spirit-world reports from the ship.
The ship is now a San Francisco-area museum, and you can judge for yourself. The museum offers regular spooky, late-night guided tours and special overnight sleep-aboards for small groups who want to investigate "our well known 'paranormal hot-spots,' " according to the Hornet's website.
Based on volunteer, staff and visitor reports, paranormal investigator Loyd Auerbach says as many as 50 ghosts roam the ship.
10. Pearl Harbor, Hawaii
It didn't take long for Anne Murata to have her first experience with the ghosts of the Pacific Aviation Museum after she started working there a few years ago.
Located on Ford Island in Hawaii's Pearl Harbor, the museum's two main buildings are hangars that are still riddled with bullets from the Japanese surprise attack in 1941.
"I was working in my office pretty late at night and kept hearing music out on the main floor," Murata says.
When she went out to investigate, it suddenly stopped. But soon she heard the murmur of men talking, as well.
"It almost sounded like a party was going on out there," she says. But again, every time she investigated, it all stopped.
"It wasn't threatening at all, and eventually I just went back to work," she says. Later, her boss explained that it was just another particularly active night with the museum's resident platoon of ghosts.
"Everyone who's worked here has had many experiences like this," she says.
The place has become a magnet for local and national paranormal investigators. The SyFy Channel's "Ghost Hunters" devoted an episode to all kinds of creepy occurrences they experienced there.
"The investigators always find amazing sounds and lights and orbs and footsteps and voices. It really is pretty rampant here," according to Murata.
One recent occurrence involved what looked like an elderly retired service member wearing a veteran's baseball cap.
"We kept seeing him over many nights sitting on various benches," she says.
One evening at closing time, a worker at the front desk, thinking it was an actual veteran, explained it was time to go and walked him to the door.
"When they looked on the security cameras, there was no one there. She was just talking to thin air."