A trio of Vicksburg marathon runners will shift from the rolling hills of the Vicksburg National Military Park to the grueling terrain of the Rocky Mountains.

Mack Varner, Dr. Robert Sadler and Terry Waller will be part of a 12-man group that will tackle the Wasatch Back Relay’s 170-mile course that begins near Logan, Utah, and ends at Park City. The race begins Friday and ends Saturday, all in one 24-hour sequence.

“It’s one long sequence of runs,” said Sadler, 55, a Vicksburg dentist. “There are 36 legs in the race and each of one of us will run three legs. You start with a guy in the No. 1 position and go right down the order to No. 12. Then you come back and do it again.”

“Each segment is about 5-to-6 miles long,” said Varner, 60, who is an attorney in Vicksburg.

The three Vicksburg runners will be joined by nine from the Jackson area.

Sadler said that a wristband is exchanged at the end of each segment. The group will compete in the Masters Level for runners aged 40-and-above.

“Delbert Hosemann from Jackson is the one who is organizing all of this. We just get on the plane and get there,” said Varner, one of the key organizers of the annual Run Thru History.

Varner, though, prefers the really long races called ultra marathons.

“I do a lot of trail runs and ultra marathons which are 31 miles. In July, I’ll go with Dr. (Robert) Abraham to a run at Lake Superior in Michigan. I do the 5K runs, but I like the marathons the best,” Varner said.

The big challenge for the three runners will not be the distance, but the altitude.

“I guess you can say it’s the scenic route,” Sadler said. “We’ll go by seven reservoirs and three mountain passes. There’s going to be a lot to see, but it’s going to be a tough run because of the altitude. It ranges from 5,000 to 8,000 feet. It’s at 6,500 to 7,000 where it really affects you,” Sadler said.

Waller has run once at high altitude at a marathon in Lake Tahoe, Nev.

“I think the altitude for this one goes up to almost 9,000 feet. I’ve done a lot of marathons, between 30 and 40. But I remember after Lake Tahoe, they told me I needed to see the doctor,” Waller said.

Varner and Sadler have run a similar sort of relay race before.

“Two years ago, we did the Hood-to-Coast Relay which starts at Mount Hood in Oregon and then runs to the Pacific coast,” Sadler said. “That was a 12-man team relay and each member ran a leg at a time.”

“We basically have the same group that ran the Hood-to-Coast two years ago, with the exception of four new people for this one,” Varner said.

The Hood-to-Coast is about 195 miles in length.

“That one was tough because it’s hard to run downhill on a mountain. It was hard for me to recover from my first leg,” Sadler said. “These types of races are also hard because you get very little sleep or something to eat between runs.”

Both Varner and Sadler have run the premier marathon in America in the Boston Marathon.

“But those were just hills in Boston. This time, we’ll be going over a mountain range in Utah,” Sadler said.