The search continues for a mother of five last seen the day before the Fourth of July holiday.

Crystal Rogers was last seen by her live-in boyfriend, Brooks Houck, on July 3, according to the Nelson County Sheriff's Office in Kentucky. Houck said she stayed up late that night and when he woke up the next morning, she was gone.

Since then, police and volunteers have worked to retrace her steps, scouring farmland and woods in the area.

But the only sign of Rogers, 35, so far was her car -- a maroon Chevrolet with a flat tire -- found along the side of Kentucky's Bluegrass Parkway, an area loved ones told police she rarely traveled.

Rogers’ keys, purse and uncharged cell phone were inside the vehicle.

“If he said he went to bed at 11 o’clock and she was still up on her phone, I can't see her just jumping in her car with a dead cell phone,” Rogers’ mother, Sherry Ballard, said at a news conference. “Crystal we love you. We're looking for you and we're not gonna stop.”

Houck said he had nothing to do with the disappearance of the mother of his 2-year-old son. He took a polygraph test and told HLN’s Nancy Grace the results were inconclusive.

"I'm 100 percent completely innocent in this,” he said. ”I want the emphasis to remain on Crystal’s safe return."

A $71,000 reward is being offered for her return.