BILLINGS -- Co-workers at Glendive Medical Center on Wednesday remembered Susan Limesand Casey as always smiling.

Casey, 34, was missing from April 12 until Tuesday, when her body was found in the Yellowstone River near Fallon.

A mother of four, she worked in Glendive Medical Center's medical records department for 10 years. Co-workers called Casey a wonderful person who embraced a passion for exceptional customer service, always making the customers a top priority, spokeswoman Cathy Kirkpatrick said.

"Our hearts go out to Susie's family," said Scott Duke, CEO at the facility. "At a time like this, words really cannot express the depth of our sorrow at this unexpected and tragic loss."

Law enforcement officials released few details about the investigation into Casey's death, which is considered suspicious.

Dawson County Sheriff Craig Anderson said his agency was contacted Tuesday after a body was seen in the river, about 1 1/2 miles downstream from the Interstate 94 bridge outside of Fallon in Prairie County. He would not comment on cause of death or how long Casey had been in the water.

Several weeks ago, hospital staff placed yellow ribbons around the medical center in honor of Casey, Kirkpatrick said. She received employee of the quarter recognition in 2005 after being nominated by co-workers, Kirkpatrick said.

"Susie was very outgoing, always offering a cheerful greeting," Kirkpatrick said.

Casey was last seen about 5 a.m. in Glendive and reported missing by her family that afternoon. Volunteers, including medical providers at the hospital, and law enforcement searched nearly 1,700 square miles of Dawson County and the Interstate 94 corridor to Billings during the following week.

The extensive search was suspended on April 17, but the investigation into Casey's disappearance continued until she was found.

Dawson County Sheriff's Office is leading the suspicious death investigation with assistance from Glendive Police, the state Division of Criminal Investigation and Prairie County.

Anderson said searchers had flown over the area where Casey's body was found a number of times, had jet boats on the river and had asked people fishing in the river to keep an eye out.

Casey was featured as a missing person on the Web site of the television show "America's Most Wanted."

On April 25, Casey's former husband appeared in Dawson County Justice Court and pleaded not guilty to a misdemeanor charge of violating an order of protection. Authorities say the Billings man, Walter Martin Larson, made 44 calls to Casey between April 10 and April 12, the day she disappeared.

Larson, 37, was arrested in Billings on April 14 and was released within hours after posting a $5,000 bond. He is being represented by a public defender. A pretrial hearing has been scheduled for June 11.

Funeral services for Casey are pending.

The Glendive Medical Center is planning a memorial service for hospital staff which will be led by the Rev. Curt Curtis, the center's chaplain.