PHOENIX (WOOD/AP) — The desperate search for a woman and boy with ties to a West Michigan company continues at Grand Canyon National Park.

LouAnn Merrell, 62, and her 14-year-old stepgrandson, Jackson Standefer, have been missing since late Saturday in a remote area of the Arizona attraction.

Both hikers are related to Randy Merrell, the co-founder of the Merrell Boot Co., a popular outdoor footwear maker owned by Rockford-based Wolverine Worldwide.

LouAnn Merrell, the wife of Randy Merrell, with her husband, stepgrandson and the boy’s mother on a multi-day hike when she and the boy lost their footing while crossing Tapeats Creek and were swept away by water.

Thursday, drones aided the search for the pair. The Grand Canyon is the only national park to have its own fleet of unmanned aircraft for finding people.

Still, the drones were unable to find the hikers, and the search was scaled back.

The Grand Canyon is consistently one of the most popular attractions in the United States, drawing nearly 6 million people last year.

But the park’s nearly 2,000 square miles, steep cliffs and mesmerizing views have often led to accidents and deaths. The park service reported over 1,000 medical emergencies, 15 deaths and 318 search and rescue incidents in 2015, the last readily available data.

The remote area where the family was hiking is at the bottom of the canyon near the North Rim, a much-less visited area of the park.