Search continues after three days of futile digging

DELTA, Utah -- Authorities planned to resume searching the Utah desert today in a nearly two-year investigation of a missing mother, after no remains turned up after three days of digging in what had been described as a shallow grave.

Cadaver dogs led police to the site Wednesday near the base of Topaz Mountain, a popular rock-hounding spot more than 130 miles from where Susan Powell was last seen at her West Valley City home on Dec. 7, 2009.

Authorities found small charred wood chips that were being taken to Salt Lake City for further examination.

"They obviously have some type of human decomposition on them because that's what the dogs are hitting on," West Valley City Lt. Bill Merritt said .

Authorities had been searching the area since Monday. On Wednesday, they said they found human remains but later said the dogs had alerted them to the site but no remains had been found.

Police plan to continue with their search for remains in the area today .

The spot is about 30 miles south of where Powell's husband, Josh Powell, told police he took his sons, 4 and 2, camping the night his wife vanished. He said they left his wife at home about 12:30 a.m. The 4-year-old confirmed the trip to police.

Susan Powell was 28 when she was reported missing after she didn't show up for her stockbroker's job.

Josh Powell is the only person of interest in the case, although he has never been arrested or charged. He said he believes his wife ran off with another man.