Sarah Loyola has faced a lot of challenges in her career managing large construction projects including work at the Jet Propulsion Laboratory, the Aquarium of the Pacific, Cedars-Sinai Medical Center and Los Angeles International Airport.

But the Southern California Edison major construction manager had to use all the creativity she could muster last year for a seismic retrofit project to cut a 12-foot by 22-foot notch in the Rush Meadows Dam.

The challenge: In this day of electric vehicles, drones and helicopters for transportation, Loyola had to go old school because the dam is in the Ansel Adams Wilderness northwest of Mammoth Lakes. The Wilderness Act of 1964 prohibits mechanized or motorized equipment without special U.S. Forest Service permission.

As a result, Loyola was only allowed to use horses and pack mules to get the crews and most of the equipment and material to the dam site in the Eastern Sierra.

“In my past career, I never had to use pack mules,” Loyola said

Except for some heavy pieces like a remote-controlled robotic jack hammer that were brought in by helicopter, the SCE crews had to go up the mountain trail on horseback from June Lake. Most of their equipment, materials, food and luggage was transported by accompanying pack mules. They made the three-hour trek using 18 horses and mules per roundtrip.

The logistics were difficult enough, but there was the human factor, too. Many in the crew had never been on horseback, much less ridden up a steep mountain trail for most of a day. So before heading out, Frontier Pack Train, the company that provided the horses and mules, gave the team a short course on how to ride a horse.

“Put your weight on the balls of your toes when you start going downhill,” said one of the pack train leaders. “When we come to the yard or wherever we are going and we stop and we’re going to get off, wait until someone comes to help you off.”

Besides the lack of horse-riding experience, the crew had to cope with high altitude – ascending from 7,225 feet to about 9,440 – and mid-summer temperatures.

Even an experienced horsewoman like Samantha Nelson, an SCE senior manager in Generation who has a “pet” thoroughbred, said it was a harrowing ride.

“It was like a roller-coaster track – you were either going up or going down,” she said. “Parts of the trail were uneven and looked very slippery and other parts were loose. On Angels Flight there was a cliff on one side.”

Loyola said she couldn’t help but think back to 1925 when SCE crews first built the dam. They had no choice but to use animals for hauling crews, equipment and materials and simple tools to construct the concrete dam, which is 50 feet high and 463 feet wide.

While also riding in on horseback, the SCE team last year had the relative advantage of computer planning, more modern tools and help from a helicopter. They completed the dam-notching project in nine weeks – six weeks ahead of schedule.

“It’s humorous,” said Loyola. “I started my career out of college working on a project for the Space Shuttle and completed a project in 2018 with mules.”