RUMFORD — Paralyzed from the waist down in a snowmobile accident, Nate Clark is fighting back far from home.

Determined to walk again and ride snowmobiles, the longtime sled racer from Dixfield is undergoing a grueling, five-week therapy regimen at the Shepherd Center in Atlanta.

Clark, 28, suffered a spinal cord injury during a hill climb race at Black Mountain ski area on Jan. 11. He broke four ribs, fractured his sternum and burst-fractured a vertebra when he flipped off the back of his sled as it traveled at more than 100 mph up the course.

“I am lucky enough to have response in three major muscles in my legs, which enable me to work out on bikes and equipment that stimulate muscle movements via electrical shock,” he said Tuesday via Facebook.

Each week, his training will intensify.

“I am exhausted after day two,” he said. “I can only imagine how I will feel after day 35!”

Clark’s accident in the hill climb that drew 76 sled riders was the only one of the night. He remembers it vividly.

“The sled I was on that night was a turbo and was built to run 21 pounds of boost,” he said. “With a turbo, you run ‘X’ pounds of boost for more horsepower. Every pound is worth about 10 additional horsepower. The higher the boost, the higher the octane needed to avoid engine detonation. I was running a mix of race gas and pump gas for those levels. The increase in boost results in higher turbo output.”

Clark, who has been riding Arctic Cat snowmobiles since he was 5 years old, said he has ridden less powerful turbos up Black Mountain without a problem.

“I have raced Black Mountain many times on several different sleds over much more demanding conditions with no incident or close calls,” Clark said. “The terrain, or course, was not the issue.”

In hindsight, Clark said he was simply riding too fast of a sled that night on too short of a hill-climb course, and without the upper body protection offered by a safety vest.

“The snowmobile didn’t hit me,” he said. “My injuries were from the impact of falling off the back of the sled.”

The sled went airborne when Clark hit one of the rolling hills on the Lower Androscoggin Trail.

“There was no significant ‘hole’ or hit, just too much speed and far too little snowmobile track for the grade of the hill,” he said.

Clark said he “had all intentions of letting off the throttle at the first good hit, but never made it that far.”

He added, “I significantly underestimated the effects of that much horsepower — 260+ horsepower — in those types of conditions. I’m not sure of my speed during the flip, but I would guess it was well over 100 mph.”

When he’s not racing sleds, Clark works as a finishing superintendent at the NewPage paper mill. He said he hopes to return to work by April.

Both Clark and his girlfriend, Michelle Perry Bernard, said they are thankful for the outpouring of support since the accident.

“I have received a tremendous amount of support from everyone at the company,” Clark said. “I am truly grateful for all the people that I work with. Getting back there is a huge motivator for me.

“The support from the entire community has been simply amazing,” he said. “I feel very blessed to have such great family and friends.”

That support group will hold a fundraising benefit for Clark from 7 p.m. to midnight on March 23, with a raffle from 7 to 9 p.m. and a dance afterward.

Scot and Cindy Grassette, owners of 49 Franklin Reception Hall and Mystic Theater, donated their building and DJ for the night.

“The benefit is needed because not all of his medical bills are covered, and other expenses that they have and will encounter,” Tara Pelletier, Clark’s cousin, said via email Wednesday.

While hospitalized after the accident at Maine Medical Center in Portland, Clark said he learned about the Shepherd Center through his brother-in-law, a native of Atlanta and a center volunteer.

Clark applied and was accepted for therapy.

“Shepherd is referred to by many as the best spinal cord facility in the country and one of the top 10 in the world,” he said. “They have a very intense rehab program and are up-front about their ‘boot camp’ style approach. The entire staff is very friendly and determined.”

Perry Bernard said Wednesday that Clark will do well at the center.

“His attitude and spirit is up and that’s what’s most important in situations like this,” she said. “To be able to walk is the No. 1 thing and, hopefully, ride sleds, not race!”

During recovery, Clark must wear a body brace for six to eight weeks whenever he’s sitting up and out of bed, she said.

“I thank God he is alive!” she said. “Being here and seeing all the people who have much worse injuries makes us thankful for many things!”

Distributed by MCT Information Services