DENVER — As a wilderness firefighter, Caleb Renno hiked over mountains until his heels bled, living out of tents and eating packaged food for weeks at a time in rugged corners of the burning West. He did not love the work, but like many young adults in southern Oregon, he knew he could always find steady pay fighting fires.

In 2008, while fighting a blaze in the mountains of Northern California, Mr. Renno and eight other people were killed in a helicopter crash, and his parents tried to seek federal benefits under a government program for the families of first responders who die on the job. But Mr. Renno, 21, was a contract firefighter, paid by a private company. The government denied his parents’ application.

“It’s just a horrible inequity,” said his mother, Catherine Renno. “These guys were doing some of the hardest firefighting there was, period. They were on the front lines. They work the line right next to the Forest Service workers. The only difference is that if one of them dies, they’re not going to get benefits.”

In life, firefighters from disparate states and backgrounds work side by side, fighting the same blazes on the same terrain. But in death, families say, they are sifted into different categories based on their official employment status.