POST FALLS - In an attempt to locate a missing Coeur d'Alene woman, Avista Utilities on Thursday closed its south channel dam to allow law enforcement to scour that part of the Spokane River, but the search came up empty.

However, some evidence has been found near the river, but Post Falls Police Chief Scot Haug declined to discuss details.

Joan Gundlach, 70, has been missing since Tuesday morning.

"The south channel (of the dam) was shut down to where no water was going through," Post Falls Police Capt. Pat Knight said. "Chances are she got outside of the south channel (with the earlier force of the water) and went downstream or there's a chance she's not even in the river.

"We're continuing to look, but we've exhausted our search in reference to the channel."

For the second straight day, a MedStar helicopter hovered over the river searching and the Kootenai County Sheriff's Office assisted.

Knight said the focus of the search will turn back to the park's trail area today. The volunteer Northwest Backcountry Search and Rescue team was going to search the area from Q'emiln Park to Corbin Park on Thursday night.

Gundlach reportedly has been suicidal off and on for several years. Suicide notes were left at both home and in the vehicle that was recovered on Wednesday at the Q'emiln Park trailhead near the dam.

Multiple agencies spent about 10 hours on Wednesday searching the park and trail and river systems.

Knight said that, although Gundlach's 76-year-old husband's behavior seemed "odd" on Wednesday, especially considering his wife was missing, he said on Thursday that "suspicious" is now too strong of a description in the case. The husband told police that the reason he didn't report her missing after finding the vehicle based on a note was that he was distraught.

"It's a missing person case with a unique twist," Knight said, adding there are no suspects or persons of interest. "It's raised some eyebrows, but we don't have a crime. There's just some bumps in the road that we'll need to investigate."

Knight said it's still too early in the case to assume anything.

Knight said investigators are collaborating with the family in the case. Gundlach's husband told police the couple have been married 30 years.

Knight said based on reviewing park surveillance, they believe Gundlach entered the park area and didn't come out.

Police don't have a clothing description for Gundlach. She is a white female, about 5-foot-8, 155 pounds with brown hair and brown eyes.

Anyone with information is asked to call PFPD at 773-3517 or leave an anonymous tip at www.postfallspolice.com.