GRAND CANYON NATIONAL PARK, Ariz. (AP) - Grand Canyon National Park officials are scaling back a search for two missing hikers swept down a stream below the North Rim.

Park spokeswoman Robin Martin says the search for 62-year-old LouAnn Merrell and her 14-year-old stepgrandson, Jackson Standefer, will continue Thursday with the use of a helicopter, drone and motorized inflatable raft.

Martin says ground teams no longer will be used because they've now checked areas that they can reach on foot.

A statement released by the hikers' families says they support the decision to scale back the search and thank all those involved in the effort.

The hikers have been missing since late Saturday when they lost their footing while crossing a stream during a multi-day hike in a remote area of the canyon.

The families of the two hikers released a statement Thursday:

This morning the Merrell and Standefer families are still praying for a miracle in Grand Canyon National Park. Today, April 20, the search for Lou Ann Merrell and Jackson Standefer will continue on a limited basis. 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 (GCNP) decision to scale back the search.

We thank the GCNP staff for their exemplary service. We know they have done everything possible since Saturday, April 15, to find Lou Ann and Jackson. We also know countless people were praying for a much different outcome than this one. We felt your prayers and were sustained by them in ways we cannot begin to describe. We are profoundly grateful for the support that continues to pour in from across the country.

We thank GCNP, the Arizona Department of Public Safety, Uintah County (Utah) search and rescue, Merrell Boot Co., SKYTEC of Chattanooga, TN, Xanterra Hospitality, and all others who volunteered their time, talents and equipment in the effort to find Lou Ann and Jackson.

GCNP is expected to release information about the search effort. Please direct all search related questions to GCNP.

We ask that you please continue to pray for our families, as our loved ones are still missing, and please respect our privacy at this time.

Thank you,

The Merrell and Standefer families