She said Joel - as his family called him - had seemed happy when she saw him on August 1, just before he set off to an Eclipse festival in Oregon.
"He was in great spirits when we saw him," she said.
He told her of his plans to attend Burning Man with a group of friends and that it would be his first time attending the event.
Mitchell said her son grew up in McAlester, Oklahoma, but had been living in Switzerland where he worked in the construction industry. He was married to a Swiss woman but the couple had no children, she said.
"He's 41, but they are always your baby," she told the paper.
"He was loving and a nice person," she said.
"Joel liked hiking and outdoors, running."
Police are investigating Joel Mitchell's horrific death, which was witnessed by hundreds of fellow revellers.
Photographs show the long-haired man racing toward the fire, dodging multiple safety rangers chasing him, and then plunging into the flames.
Pershing County Sheriff Jerry Allen said Mitchell ran through two layers of security officers at 10.30pm on Saturday during the Man Burn event at the counterculture festival.
He was dragged from the flames by firefighters and then flown to hospital.
About 70,000 people attended this year's Burning Man art and music celebration in the Black Rock Desert, which ends today.
The nine-day festival culminates with the burning of a towering 12m effigy made of wood, a symbol of rebirth, which usually happens the Saturday before the US Labor Day holiday. It's followed by the burning of a temple on Sunday.
Revellers have tried before to run into the flames while the man is burning and people have reportedly been injured trying to get a piece of the spectacle as a token and going through the hot coals.
According to festival organisers, attention seekers, such as streakers; people who are so high on drugs or drunk that they don't understand the danger; and the suicidal are the most likely to rush towards the fire. Securtiy staff are trained to stop them before the figure is set alight.
Allen said rangers create a human chain to prevent people from accessing the fire. He said Mitchell was the first person to have broken all the way through and the only fatality he had seen in 15 years on the job.
"People try to run into the fire as part of their spiritual portion of Burning Man," he said.
"The significance of the man burning, it's just kind of a rebirth, they burn the man to the ground, a new chapter has started, it's part of their tenets of radical self-expression."
Organisers cancelled scheduled "burns" throughout the site but confirmed the highly anticipated Temple burn at 8pm local time would go ahead.
In the meantime, revellers were urged to take advantage of on-site trauma counsellors, look out for one another and catch up on sleep.
"We're aware this has affected not only those who responded immediately on the scene, but also those who witnessed it, and our Black Rock City community more broadly," Burning Man said in a statement posted to its site.
"We are working to make resources available to those affected. Emotional support teams have been made available to participants and staff.
"Now is a time for closeness, contact and community. Trauma needs processing. Promote calls, hugs, self-care, check-ins and sleep."
