However, the searchers on the ground won't be used because they've now checked areas that they can reach on foot, Martin said.
The hikers have been missing since late Saturday when they lost their footing while crossing a stream in a remote area of the Grand Canyon.
A statement released by the hikers' families thanked the searchers and said the families "are still praying for a miracle in Grand Canyon National Park" but support the decision to scale back the search.
"After carefully considering all the information available to us, and based on our personal knowledge of the search area, we support Grand Canyon National Park's ... decision to scale back the search," the statement said.
Both hikers are related to Randy Merrell, the co-founder of the Merrell Boot Co., a popular outdoor footwear maker.
LouAnn Merrell, the wife of Randy Merrell, was with her husband, stepgrandson and the boy's mother on a multi-day hike when she and the boy lost footing while crossing Tapeats Creek and were swept away by water.
LouAnn Merrell has been previously referred to as Lou-Ann, which is how she identifies on her Facebook page, but a spokesman for the families of both hikers said it is spelled without a hyphen.
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.