Air Force veteran Daniel Kester of Tucson studied the transition of military veterans into civilian society to earn his Ph.D. in education.

But the retired intelligence specialist still needed help with his own transition issues, as he stepped away from a military career that included combat duties in Iraq and Afghanistan and left him with post-traumatic stress syndrome.

Kester found some of that help in 2015, when he participated in a No Barriers Warriors Veterans Expedition through the Grand Canyon, through a program sponsored regionally by defense contractor Raytheon.

Conducted by No Barriers USA, a nonprofit based in Colorado Springs, the No Barriers Warriors expedition program teaches vets with disabilities to overcome personal barriers through wilderness challenges.

Raytheon, the Tucson region’s biggest employer, is partnering on the No Barriers Warriors expedition program regionally for the fourth year.

This year, the company is sponsoring a dozen wounded warriors from Arizona, New Mexico, Texas and southern California for a 10-day trek through the Wind River Range in Wyoming in August.

Kester, who now works in mission control for the Tucson-based high-altitude balloon startup World View Enterprises, said he gained new confidence and bonded with fellow vets on his 2015 trip.

“It definitely helped,” said Kester, who retired as a senior master sergeant last year after a 20-plus year career including 11 years on active duty and stints in the Air Guard and Air Force Reserve.

“It’s one of those things where you put yourself in a situation that’s out of your comfort zone, that you’re not really sure you’re able to accomplish, but with the help of your support group you’re able to get through. They made it very positive.”

Though unlike military survival school, food was provided, participants had to manage their way through a series of challenges while rough-camping in the wet.

And though the Army vets often jokingly threatened to test Kester’s Navy skills by throwing him out of the raft, Kester and his colleagues made it through, together.

The toughest parts of the trip included helping one participant who had difficulty walking straight because of a traumatic brain injury hike out of the canyon.

“We had to help get him out of the canyon and up Bright Angel Trail, which is a mile straight up,” he recalled. “Some of the trail is as wide as a sidewalk with a 7,000 foot drop, and we’re holding onto each other.”

And in a sense, they are still holding onto each other.

“I’m still in touch with several of the people in the group on Facebook and other places,” Kester said. “They’re great guys and helped me when I’ve had issues afterward, and when they have issues, we call each other and help each other out.”

There are plenty vets who need such help.

About 2.5 million veterans have served in Iraq, Afghanistan and other parts of the world, and the U.S. Department of Veterans Affairs estimates that between 11 to 20 percent of those veterans have been diagnosed with PTSD, a mental-health disorder with symptoms including flashbacks, anger and constant fear of danger.

As of 2015, some 1.8 million veterans who served since the first Gulf War in 1990 were receiving benefits for a service-connected disability, according to the VA.

Raymond Davis of Phoenix, a former Navy hospital corpsman one of three Arizona veterans picked for this year’s No Barriers trip to the Wind River Range, said he hopes to find help dealing with PTSD and a traumatic brain injury he suffered in Iraq in 2006.

“A lot of veterans I know, for whatever reason, just have a hard time blending in with everyday people,” said Davis, 39, who works as an advanced medical support assistant at the Phoenix VA hospital. “I’ve had some issues just adjusting, so for the last few years I’ve just been on a downward spiral of emotions, just finding my place.”

Davis said the trip combines things that have helped him in the past.

“I always find I do better if I spend sometime outdoors or in a physical challenge, or getting together with the people I served with,” he said.

Davis says he’s been through VA counseling and though he doesn’t know his fellow Wind River trekkers he has no doubt they will pull together through the challenges.

“I know other veterans who have been through the same thing, so were not going to give up on each other.”

Kester, who spent a year and a half heading Pima Community College’s veterans services department, said it’s “critically important” that disabled vets seek help.

“One of the things I found in my dissertation is that vets aren’t the type of people who ask for help,” Kester said. “That’s one of the things you have to overcome, you have to be OK with just asking for help. There’s a lot of help out their from all sorts of institutions, and especially other veterans who will step up and help out any way they can.”

Contact senior reporter David Wichner at dwichner@tucson.com or 573-4181. On Twitter: @dwichner

Senior reporter covering business and technology for the Arizona Daily Star/Tucson.com