Montgomery County resident Katherine Slover helped rescue passengers and 12 cars from White’s Ferry after it broke from its cables on the Potomac River. (WUSA9)

Katherine Slover was sitting in her car with her husband at the White’s Ferry landing in Montgomery County on Friday afternoon when she saw something odd. The underwater cable that guides the ferry across the Potomac River between Maryland and Virginia had snapped, she said. It “shot up in the air and smacked down on the water, and water shot up in the air. It was beautiful.”

Then the ferry took a right and started heading downstream.

After a brief discussion with her husband about whether this was standard navigation for the ferry, Slover hopped out of the car and began running along the bank while passengers watched and the boat captain yelled frantically for help.

Slover navigated her own perilous route to the river’s edge, and with instruction — and ropes — from the captain tied the boat to several trees before it could float off toward Washington. Twelve cars and about 20 passengers were aboard the ferry, but no one was hurt and the ferry was back in operation later Friday night, said Matt Swensen, general manager of White’s Ferry.

By the time Montgomery County Fire and Rescue boats arrived, the passengers had all reached shore with the help of Slover and others. “We’ve got to get her an application,” fire spokesman Pete Piringer said, “and have her come work for us.”

Katherine Slover helped rescue a ferry that was drifting downstream on the Potomac River. (Courtesy of Katherine Slover)

“It was exciting,” Slover, 49, of Potomac, Md., said Saturday. She had been planning to take the ferry to Leesburg, Va., from Maryland’s Dickerson port. “The current was going quickly and trying to swing the bow around, and I barely got the rope around the tree in time, with my shaking hands.”

White’s Ferry, in operation since 1782, is the last ferry operating on the Potomac and can carry up to 24 cars, its owners say. On Friday, it was making its four-minute journey from Loudoun to Montgomery when the guiding cable snapped about 2:45 p.m., Piringer said.

Slover estimated that the boat was midway across the river when it took the sudden detour. As she ran along the river, she could hear the captain calling for help. “He was frantic,” Slover said. “People were watching the ferry go downstream. It was unbelievable. I just started chasing it.”

As the captain steered the ferry toward the riverbank, Slover tried to track it along the shore but reached a steep embankment with a creek at the bottom. A few yards inland, “a tree had fallen across the creek” about 10 feet above the water, Slover said, and she “got down on all fours” and crawled across to the other side.

Dusty Slover, Slover’s husband, said that because of the creek, others couldn’t or wouldn’t scramble across the mossy fallen tree to help. “Katherine was the only person between the ferry and disaster and in a position to rescue the ferry, the cars and the passengers from drifting down the Potomac,” he said.

Emerging through the trees, “I could hear the captain,” Katherine Slover said. “He yelled, ‘Is anybody there? Help! I need help!’ ”

The boat was aground, but not solidly. Slover yelled to him, and the captain threw her a rope. “I tied it twice around the tree,” she said. “By the time I did that, the boat had swung around, and we could both hear the tree cracking.”

The captain tossed her a second rope, which Slover said she tied around a larger tree. But she was still afraid that the current would be too powerful, so as they waited for help, the captain tossed a chain from the boat and she wrapped that around a tree, too, her hands now bleeding, her husband said.

Swensen said that White Ferry’s 20-foot aluminum work boat soon arrived to stabilize the boat and help passengers disembark. The boat then pushed the ferry about 500 yards back upstream. It was docked and the cars off-loaded by 3:45 p.m., Piringer said.

Piringer said the ferry’s cable also snapped about five years ago, but no one was injured in that event, either. He said Friday’s passengers climbed off with Christmas shopping in tow, though Slover said some told her that they feared what might have happened had the ferry continued floating downstream.

“She was the savior,” passenger Ted Clarkson of Gaithersburg told the Germantown Pulse. “Once we hit the bank of the river, the pilot was frantically calling for help,” he said.

“We are all lucky that this happened on a pretty day,” Slover said, “because I’ve been on the river when it’s been very windy and choppy. The captain did a great job, but he couldn’t leave the boat and needed a set of hands on land to help secure it. I was just happy to help.”