YAKIMA, Wash. -- Most days you can find Cecelia Downey out looking for her 58-year-old son, Larry Riegel.

She and her daughter, Candy Jarvis, are out every day posting fliers at restaurants and businesses across the Valley, seeking information about Riegel's whereabouts.

A contract pilot for Cub Crafters, he planned to attend a dinner at his mom's house on Pleasant Avenue in Yakima the day after Christmas. But he never showed.

The family, desperate to find him, has been working closely with a Yakima police detective, while also creating a Facebook page and Web site, www.findlarryriegel.com.

"We've got posters from Pine Mountain to Moxee clear to the Lower Valley and to Roslyn," Downey says. "I try to keep busy. Every once in a while, it hits hard."

Riegel is among the nearly 200 missing person cases reported in Yakima County every year. Yakima County Sheriff's deputies handled roughly 130 missing persons cases last year. And Yakima police saw about 50, averages that have held steady over the past decade.

There are only seven open cases at each department, one of them dating back to 1989.

Most of the cases are solved within a few days or weeks, authorities say.

Overdue hunters, hikers and snowmobile operators make up the bulk of the cases deputies handle. Other times people just want to be left alone, and they simply drop out of the lives of their families and friends, says Stew Graham, chief of detectives at the Yakima County Sheriff's Office.

"There's a million reasons under the sun why people step out of their lives, and eventually they'll step back in," Graham says. "There's a wide variety of resolutions to that."

One case in point is that of Teri Smith, who had family and authorities worried after she went missing in September 2004.

Smith, then 40, was last seen leaving Target. Her Chevrolet TrailBlazer was found in the parking lot with her purse, money, keys, shopping bag and cell phone inside.

Four days later, she wandered into Yakima Regional Medical and Cardiac Center dazed, dirty and dehydrated. She apparently suffered a nervous breakdown.

"Usually it will be somebody who just leaves home and doesn't tell anybody," says Yakima Police Sgt. Tony Bennett. "Usually it may be someone who just wants to get out of a situation."

Rarely do missing cases involve foul play, authorities say. But when they do, the outcome can be devastating for the families they leave behind.

Bennett points to the case of 14-year-old Francisca Hernandez-Ramirez of Sunnyside who was last seen in October 2008 at a party in Outlook. Her body was found in a canal four months later, with her throat cut.

"That was terrible," Bennett says. "Also, thank God that it's very rare."

Sunnyside police sensed foul play from the start and posted fliers in local schools.

After hearing that the girl's body had been dumped in a canal, deputies borrowed under water equipment to look for her.

Bennett says all missing persons cases are handled by the major crimes task force. After someone is missing for a month, local agencies send dental and any other records of the person to the Washington State Patrol's missing and unidentified unit.

"We really don't hold back," Bennett says. "We really pour our resources into them."

Eventually the person's information, such as dental records or DNA, is forwarded to the National Crime Information Center's Missing Persons File, which compiles records for the FBI.

According to the federal agency, there are more than 102,000 active missing persons cases in the country. In 2008 alone, there were more than 778,000 such cases reported. Most of them were resolved.

Oftentimes, cases are left open because authorities aren't alerted when missing people return home, Bennett says.

"Sometimes people will show up and the family, friends -- even the people that report the missing person -- don't think to call police," he says. "We would like to clear them. We'd hope that someone would call so we can close out the case."

When a child goes missing, Yakima police immediately search the home and contact friends and neighbors, comb parks, anywhere the child may frequent.

Information about the child's friends, such as addresses and phone numbers, is crucial to a case.

"You'd be floored at the number of people that don't have that information," Bennett says.

When an adult goes missing, police make a similar effort to contact friends and family and make routine follow-ups until the person either returns or is found.

"We just tell them not to give up, and keep looking," Bennett says. "You can't give up -- it's your family."

In Yakima, Riegel's family has continued to actively search for him and has even compiled a 36-page investigation by talking to everyone who had been part of his life. Relatives remain convinced he wouldn't have just dropped out of sight -- or moved somewhere else -- without telling his family.

His mother drives around in a car plastered with bumper stickers seeking him, and has done radio interviews as well. The family has even put Riegel up on eBay to sell him, in hopes of finding him.

Police say at this time there is no evidence that Riegel was the victim of a crime, but the family remains suspicious.

His sister, Susan Riegel Vaughn of Snohomish, Wash., can't imagine her brother would have intentionally missed dinner.

She says she spoke with her brother for about 20 minutes by phone two days before the Dec. 26 dinner, and that he seemed upbeat.

"He just had a birthday, and I was kind of joking around and told him he was getting old," she recalls. "We laughed, we joked -- it was really a good conversation.

"He asked me what he should bring (to dinner), and I said, 'Nothing.' I just wanted him to show up."

OPEN MISSING PERSON'S CASES IN YAKIMA COUNTY

Yakima County Sheriff's Office

* Samantha Rios, 20, was reported missing in March 1992. She was last seen boarding a bus in White Salmon bound for Yakima.

* John D. Whitner, 48, was reported missing in January 1995 by family members who said they had not seen him for weeks.

* Roger M. Seawright, 34, of Toppenish was reported missing in July 1998 after he didn't return from a store to get ice.

* Reyes S. Macias, 42, of Selah was reported missing in July 1999. Family members said they left their house briefly and that he was gone when they returned.

* David W. Door, 39, of Terrace Heights was reported missing in October 2001 after his empty boat was found floating in Lake Chelan.

* Linda M. Adams, 15, a chronic runaway, went missing from Pomona Road in Yakima in 1978, but her disappearance wasn't reported until 2004, at the request of the Green River Task Force.

* Jesus Gus Rodriguez, 35, was reported missing after his burned car was found on Jan. 23, 2005, in an orchard on Summitview Road. His remains were not found in the car.

Yakima Police Department

* Kathleen R. Paulson, 52, a transient, was reported missing by family in 2004.

* Sally Stromberg, 51, a transient, went missing some time in 2005.

* Gregory L. Holt, 58, who lived in the 3600 block of Fairbanks Avenue, was reported missing in February 2008 by his landlord.

* Jose Ortega Jimenez, 26, worked as a laborer in Naches. Fellow workers reported that he ran from the work site in March 2008, and no one has seen him since.

* Juan L. Hernandez, 28, was originally from Yakima but moved to Seattle. He was reported missing in July 2009 by family who said they had not heard from him for two months.

* Joseph E. John, 19, was reported missing by family in January 2010.

Help find Larry Riegel

* Anyone with information is asked to contact Yakima police at 509-575-6200 or Susan Riegel Vaughn at 425-293-5564. More information can be found at www.findlarryriegel.com.

* Phil Ferolito can be reached at 509-577-7749 or pferolito@yakimaherald.com.