Some people look at the river and are in awe, others look at the river and say “let’s run over it.”

A hundred feet above the churning, muddy waters of the mighty Mississippi River, and about a hundred yards from its banks, more than 300 people stand ready like bulls about to burst from a chute.

A small, wiry man with white hair and a big voice — courtesy of his bullhorn — gives some last-minute instructions that include a warning to stay away from a swarm of bees a mile and a half ahead. A few seconds later he presses the button on an air horn and the horde is off, some running, some walking.

They’ve embarked on the 27th annual Over the River Run, a 5-mile race across the Old U.S. 80 Bridge that takes place on the second Saturday each October. It’ll take the fastest of them about 30 minutes to make it there and back, the slowest more than two hours. For all of them, it’s a chance to enjoy a rare journey over the fabled waterway and partake in an event that has become one of Vicksburg’s biggest community gatherings each year.

“Where else do you get to run over the river? You forget it’s here. Then you see it, and it’s like, ‘God, this is awesome,’” said Kristi Hall, a Vicksburg resident who finished first in the Over the River Run’s women’s division five times. “I love the bridge and the party afterward. Everybody in Vicksburg goes to this and the Run Thru History, so you get to catch up with everybody.”

More than 800 people registered for the 2015 Over the River Run, which was started in 1983 as a companion race to the well-established Run Thru History. The latter is a 10-kilometer race that takes place in March in the Vicksburg National Military Park.

From 1983-88 the Red Carpet Run followed a similar, but shorter, 4 ½-mile path through the Park. It shifted venues to the Old U.S. 80 Bridge in 1989, changed its name to the Over the River Run and became a 5-mile run and race walk and 1-mile fun run.

Mack Varner, a longtime member of the Run Thru History organizing committee, credited his fellow committee member Bobby Abraham with the idea of changing the name and venue.

“It was the Old Mercy Hospital Run,” Varner said, referring to the race’s original sponsor. “We talked to folks from the Bridge Commission and suggested moving it over here, because we already had a run in the Park.”

Nearly 600 people participated in the first Over the River Run in 1989, and the number waxed and waned over the years. It hit a low point in 2008, when only about 400 people signed up, but has climbed nearly every year since. Participation peaked at 829 people in 2013, which marked the first time the Over the River Run had more runners and walkers than its cousin the Run Thru History.

In 2006, the race shifted its date from the heat of early September to the cooler second weekend of October, which helped increase turnout.

Varner said the race’s appeal to runners is its uniqueness and course layout.

“There’s nowhere else you can run across the Mississippi River,” he said. “It’s just unique and beautiful, and flat as opposed to the Vicksburg Military Park. It’s a good length, and we get a good crowd.”

Varner’s first statement was a bit off. Several river towns between Louisiana and Minnesota — including Greenville in north Mississippi — have runs that cross the river. Few make it such a dominant feature, however.

During the event, if they take the time, runners can look to their right and see barges and towboats pass underneath. Later in the race, trains often rumble alongside runners as they make their way back from Louisiana.

The trains’ crews will sometimes step out of the locomotive to watch and wave at the passersby. There’s a sizable gap between the roadbed where the runners are competing and the railroad bridge adjacent to it, but from a distance it looks close enough for runners and engineers to high-five each other as they head in opposite directions.

“I don’t know if you feel the bridge moving, but the sound rumbles through your body and you feel it moving,” said Harrisville resident Barbara Duplichain, who has won the 5-mile race walk portion of the Over the River Run a dozen times.

That sort of experience is one runners and walkers from all over Mississippi and the United States — they came from as far away as North Carolina for last year’s Over the River Run — come to Vicksburg for. It’s also one the locals lap up when given the chance.

Longtime residents fondly recall the days of driving across the tight, two-lane U.S. 80 Bridge, but it hasn’t been open to vehicular traffic or to the public on a daily basis since September 1998.

The Over the River Run is one of a handful of special events each year when it opens to pedestrian traffic, and only then for a short time. That makes it a special treat not to be missed.

“It’s not something you get to do. You’ve got to do this,” Vicksburg resident Brandie McMullin said after the 2015 race. “I was sick this week and had to get shots to run. I wasn’t missing this. If they open this up, I’m going to come and run. This is it.”

Like McMullin, Hall said the Over the River Run was one she never misses.

“I just like it, and it’s what I do,” Hall said. “I run three races a year — the Run Thru History, the Watermelon Classic (a 5K in Jackson on July 4) and this — whether I’m pregnant or limping. I don’t know what else to do those weekends.”

The after party helps, too. Ameristar Casino sponsors the race and hosts a celebration in its parking lot afterward with live music, children’s entertainment and adult beverages.

It’s as big a draw as the picturesque setting.

“All the Vicksburg races have free beer and good organization,” said Collin Johnson, a Clinton resident who finished second in the 2015 race.

Hall, though, said the ultimate appeal of the race comes back to one thing.

“It’s just the river,” she said. “Getting to be that close to the Mississippi River is incredible. The whole town shows up for a great party and it’s just fun.”