Authorities say they will likely need a helicopter to search for a group which became stranded in the desert near Buckeye.
The Maricopa County Sheriff's Office said two adults and an unknown number of children were four-wheeling for much of the day in the desert off of Sun Valley Parkway.
The group became stranded, and called 911 for help.
Deputies said the chopper was needed because the people weren't certain of their location, making it hard for crews to know how best to reach them.
Authorities responded to an area of Sun Valley Parkway south of Bell Road as a place to begin their search.
Sun Valley Parkway connects Surprise and Buckeye by looping around the White Tank mountains, home to White Tank Mountain Regional Park and Skyline Regional Park
No other information was immediately available.