(WESTMINSTER, Colo.) -- Authorities in Colorado are reviewing recent phone calls and social media clues in the disappearance of a 10-year-old girl.
Jessica Ridgeway left home at 8:30 a.m. on Friday to walk three blocks from her Westminster, Colo., home to meet friends for the walk to school. It was a route she took every day, but this time she never got there.
On Saturday, an army of eight hundred volunteers scoured trails and hillsides near Jessica's home.
"Right now they're just asking us to find anything that's out of the ordinary, any kind of evidence we could find," said volunteer Monty Yanker.
Police officers and FBI agents manned road blocks, asking drivers if they had seen or heard anything out of the ordinary.
Officers also canvassed neighborhoods, but the day yielded few leads.
No organized searches are planned for Sunday, authorities said.
An Amber Alert was issued Friday night for the 10-year-old, nearly eight hours after she disappeared.
When Jessica didn't show up for class, school officials called her home.
But Jessica's mother, who works the overnight shift at a tech company, was asleep. She didn't get the message, which delayed her calling police.
"When we start with an eight-hour delay, or a delay as substantial as this, the distance that she could have wandered even on her own just gets huge," Westminster Police Detective Trevor Materasso said.
Police say that Jessica's father, who lives out of state, is in a custody battle with Jessica's mother. Police do not believe Jessica is with him, but are not ruling anyone out.
"We don't have a person of interest. And we are going to look at every angle multiple times," Materasso said.
Jessica was last seen wearing blue jeans, black boots, a black puffy jacket, and pink and purple glasses, ABC affilate KMGH-TV in Denver reported.
Copyright 2012 ABC News Radio