Dogs have accompanied man on the hunt since time immemorial. Though the bow and spear has given way to the rifle, and hunting is no longer necessary, dogs continue to prove their dedication on the nation's battlefields.
Enter one of the largest military kennels in the country, that of Peterson Air Force Base's 21st Security Forces Squadron Military Working Dog section.
It is home to 14 German shepherds, Belgian Malinois, and one very friendly Lab named Penny.
The strong scent of canine musk and the din of the dogs can be overpowering to the uninitiated, but to the handlers it smells like home. Their day begins at 4 a.m., when they arrive at the kennels to feed and check on their dogs. Days, which typically end at 5 p.m. but can run well past midnight, consist of endless training.
The airmen are also always on call, and always armed, should they need to respond to requests from local law enforcement or other military in the area. They have also been called on to assist the Secret Service in guarding VIPs who visit the region.
Sit, lay, stay, heel
Outside the kennels is the obedience yard, where handlers take their dogs every morning to reinforce their training. The yard contains several concrete obstacles, designed to simulate windows, drainage pipes and rooftops.
The 3-year-old Belgian Malinois Uumbro and his handler Staff Sgt. Keenan Mondragon started slow, practicing variations on the four basic commands. Uumbro sat, laid down, returned to Mondragon's side or stayed put depending on his handler's prompts. The last seemed to be the most challenging, as Uumbro appeared to dislike leaving Mondragon's side. The two have been training together for several months.
Mondragon explained how handlers put their dogs in unusual positions, such as on top of obstacles or on the side of inclines, to reinforce basic behavior in different situations.
"Sometimes we try and set our dogs up for failure so we can teach them," he said.
Uumbro, familiar with the layout of the obedience yard, attempted to complete the course from start to finish. Mondragon called him to a halt at random times, however, to reinforce the basic commands.
After running the course to Mondragon's satisfaction, it was time for attack practice.
Bite far worse than bark
To demonstrate an integral facet of military working dog training, Staff Sgt. Shawn Kaup donned a bite suit. The cumbersome padded suit, which resembles a giant black puffy winter jacket, is designed to defend against Uumbro's bite, which can exceed 230 pounds of force.
Kaup approached Mondragon under the watchful eye on Uumbro. The unwieldy airman started by shaking hands with Mondragon, but then become increasingly belligerent in his motions. Uumbro's black ears slowly flattened against his sandy colored head. All 77 pounds of his muscular frame tensed, and his gums curled back to reveal gleaming white fangs.
When Kaup shoved Mondragon, Uumbro lurched forward, clamped his bone-crunching jaws around Kaup's extended arm and swiftly took him to the ground.
After Mondragon called off the attack, the fury in Uumbro's eyes and his snarling countenance was replaced instantly with a docile look and a slobbery tongue. He brushed up against Kaup, waiting to be reassured he had done well.
Mondragon and Uumbro, along with the help of several other handlers, who took turns as padded targets, demonstrated other behaviors, including chasing down, subduing and guarding prisoners.
For the dogs, knowing when to hold back is almost as important as knowing when to attack. Mondragon and Uumbro demonstrated a behavior called standoff.
He prompted Uumbro to attack Kaup, who was standing a few hundred yards away. Before the charging canine could slam teeth first into his target, Mondragon bellowed to Uumbro, who skidded to a compliant halt.
"Unlike a bullet, our dogs can be recalled," Mondragon said.
Boots, paws on the ground
Staff Sgt. John Kroll and Nadja, a 4-year-old German shepherd, returned from a deployment in Afghanistan in December.
They assisted units to uncover weapons caches, capture high-value targets and conduct presence patrols. "I think she's more reliable than any guy out there with a metal detector," Kroll said.
The bond between Kroll and Nadja appears to transcend teamwork. One is an extension of the other, and both react instinctively to the other's movements.
"We're going together, we're coming back together," Kroll said. "We're a team."
The two demonstrated what a typical patrol down a dusty, uncertain road would look like. The path was strewn with rock piles and abandoned construction pylons, any of which could conceal a deadly explosive or a stash of weapons.
Kroll was dressed in full combat gear. The handlers strive to recreate scenarios as they will be presented to their dogs during deployments.
Kroll kept Nadja on a 26-foot retractable leash. She probed the terrain ahead, without getting too far from the safety of her handler. Sometimes she identified irregularities in her surroundings, like disturbed earth or oddly placed objects such as stacked rocks. Other times Kroll commanded her to investigate by calling out a direction. Each time, Nadja stopped her roving, walked dutifully over and sniffed out the threat.
It's a game to her, Kroll said. The dogs know what they are expected to do, and they carry out their tasks for a reassuring word or a comforting pat from their handlers.
"Once they find that thing, and you're giving them praise, that's where heaven meets earth," Kroll said.
End of the trail
Handlers such as Mondragon view the inevitable separation of dogs and their handlers as natural progression. He recognizes the way to advance his career is to work with as many dogs as possible. But that doesn't mean switching partners is easy.
"It's always hard to lose a dog and watch someone else pick them up," he said.
Nadja is Kroll's first dog, and he expects to have a harder time when he inevitably has to leave her behind.
The war-hardened veteran said he will cry on the day "they take her away from me."
Numerous military working dogs have been killed in action assisting U.S. forces during military campaigns. Much like the sacrifices of their fellow two-legged soldiers, the lives of military working dogs do not pass unacknowledged.
Kaup said when a unit loses a dog - a partner, he corrected himself - they hold a memorial service. Tears are common.
"Knowing that your partner has at some point saved your life makes it worth it," he said.
Still, Kroll wouldn't trade the times with Nadja, good and bad, for anything. Their bond, formed through hours of interaction and a deployment to a hostile and unpredictable land, will last far longer than their service together.
"I was all she had," Kroll said. "And she was all I had."