CHEYENNE, Wyo. — Investigators once again are preparing to search a deep lake near Pinedale for the bodies of a woman and her two children murdered in rural Fremont County more than 30 years ago.

Authorities searched Fremont Lake in neighboring Sublette County in late 2013 and again last summer for the bodies of 32-year-old Virginia Uden and her sons, 11-year-old Richard Uden and 10-year-old Reagan Uden.

Ice remains on the lake but a search using a boat and sonar equipment will resume once the weather warms up sufficiently in May or June, Wyoming Division of Criminal Investigation Deputy Director Kebin Haller said Thursday.

"We are certainly going to move forward with our effort, to give it another try," Haller said. "There were a lot of lessons learned from the last venture."

The Sublette and Fremont county sheriff's offices, as well as a search and rescue team from Sublette County, will take part in the search alongside the state authorities.

The whereabouts of the three is among the few unresolved questions in two apparently unrelated murder cases involving an elderly Chadwick, Missouri, couple. Both cases went unsolved for decades.

Last May, a jury in Cheyenne found Alice Uden, 76, guilty of first-degree murder for shooting ex-husband Ronald Holtz, 25, in the back of the head as he slept in late 1974 or early 1975. A judge sentenced her to life in prison.

Uden's husband, Gerald Uden, 72, is serving life in prison for shooting Virginia Uden and her two sons with a rifle in the Pavillion area in 1980. Virginia Uden was Gerald Uden's ex-wife.

Gerald Uden pleaded guilty soon after he and Alice Uden were arrested in southwest Missouri in the fall of 2013.

He told a courtroom he put the bodies in barrels and initially stashed the barrels in a mine. He said he retrieved the barrels sometime later and used his boat to dump them in the lake.

The search for the remains is a big challenge by any measure. Fremont Lake measures 10 miles long and about a mile wide. At 600 feet, it's among the deepest lakes in the U.S.

Last summer, the search zeroed in on an area of the lake called the Narrows. This year's effort will expand to parts not yet searched, Haller said.