MORGAN HILL — Early on a stormy Saturday morning, a small group of searchers prepared to plunge down a steep, muddy ravine into thick underbrush when a rainbow suddenly appeared.

They admired the unexpected sight for a moment, a glimmer of beauty amid the grim task ahead — searching for Sierra LaMar.

Sunday marks the two-year anniversary of when Sierra, a pretty 15-year-old cheerleader, vanished on her way to a school bus stop in an unincorporated area near Morgan Hill.

Antolin Garcia Torres, a 22-year-old former supermarket employee charged with her kidnapping and murder, sits in Santa Clara County Jail. Sierra’s body has never been found.

But each Saturday a couple dozen dedicated volunteers still scour rural South County, hunting for her remains or anything that might offer a clue in the case.

Searchers brave nature’s obstacle course of rain, 100-degree heat, creeks, fallen trees, rattlesnakes, wasps and poison oak — all with the same goal. They hope to bring closure to a case that made national headlines, provoked outcry and has tugged at Bay Area heartstrings.

“We want Sierra home,” said Marie Rankin, 48, of Pleasanton, taking a break from carefully examining foot-deep water in Coyote Creek. “Not finding her has just been torture for the family. That’s why it’s so important to be out here doing this.”

Since the Santa Clara County Sheriff’s Office cannot share investigative leads — to avoid jeopardizing the criminal case — searchers have few details about Sierra’s abduction. So it’s essentially a needle-in-a-haystack quest.

Sheriff’s spokesman Sgt. Kurtis Stenderup said the department, which continues to actively work the case, wishes it could do more to help the volunteer effort.

“It’s a little bit of a Catch-22 for us because we just can’t talk about the investigation with them,” Stenderup added. “But we appreciate all the help that they continue to give us. There’s no way that we could be going out there every weekend with search teams two years later. We just don’t have those kinds of resources.”

Looking ‘rain or shine’

So volunteers, who mostly do not have any formal search training and use high-tech tools such as Google Earth to help plot their strategy, keep looking. They focus their efforts roughly within a 15-mile radius from where the teenager lived, conducting countless searches in often rough terrain.

“Rain or shine, we’re out there,” said Al Perez, a retired landscaper from San Jose, wearing two buttons bearing Sierra’s smiling picture.

And despite a steady downpour, “Team Sierra” gathered on a recent Saturday at Central High School, where the search center is located. Steve and Marlene LaMar, the divorced parents of Sierra, greeted searchers with warm hugs. Five women, known collectively as the “kitchen ladies,” prepared breakfast.

“We’re the ones who are too old to search through the mud and woods,” said M.A. Samuelson, 67, of San Jose. “But this is our way of helping.”

In another classroom, large maps of South County adorned a wall.

“There were hundreds of people showing up that first week,” said search coordinator Roger Nelson, 56, of Morgan Hill. “I was just hoping that someone would tap me on the shoulder and say: ‘We found her safe. She was in Mazatlán. She’s grounded for life, but she’s on her way home.’ But that obviously didn’t happen.”

When Sierra initially disappeared, as many as 750 people joined the search. On this dreary and blustery morning, there were 25 hardy volunteers and an energetic French mastiff named Rocco. They held hands in a circle and prayed, then divided up into three teams.

Most didn’t know the LaMar family before Sierra went missing. Some are drawn here for deeply personal reasons. Kelby Jones, of San Rafael, is the brother-in-law of Marc Klaas — the father of Polly Klaas, the Petaluma 12-year-old who was abducted from her home and murdered in 1993.

Others feel compelled to help because they can only imagine the grief that the family is experiencing.

“I have a daughter about the age of Sierra,” said Morgan Hill resident Robert Beasley, 54, a financial analyst for a semiconductor company and father of three.

He didn’t need to say more.

That sentiment is why many searchers wore T-shirts featuring Sierra that read: Everyone’s Daughter.

Jones’ team of seven volunteers drove to a parking area roughly 7 miles from where Sierra lived. Wearing rain gear and backpacks, and carrying walking sticks and shovels, they studied a search grid and photographs. Then, for the next 3½ hours, they methodically followed a rugged stretch of the Coyote Creek that runs along the northbound side of Highway 101.

The clothes of Rankin, Beasley and Sheila Gokey soon were filthy as they probed the shallow water. Jones, often working the thick underbrush, ripped his worn jeans.

The reality is that the searchers have devoted so much of their time fervently hoping to discover something terrible.

“She’s alive in our hearts,” said Barbara Hammarstrom, of San Jose. “But we’re looking for anything from bone scatter or a burial site. That’s why I say the people I’ve met doing this have enormous hearts.”

Extended family born

Team Sierra also assembled on Feb. 13 in Santa Clara County Superior Court when Garcia Torres pleaded not guilty to the abduction and murder of the Sobrato High School student. In a gesture of solidarity, Sierra supporters wore red Converse sneakers — which the teenager loved to wear.

Marlene LaMar hopes the continuing search reminds the public that Sierra hasn’t been found and maybe someone has information that could be crucial.

But there is something else, too.

Out of an unspeakable tragedy, an extended family has been born.

For example, a few weeks ago, the volunteers ended a search day early to be with Perez — the San Jose retiree — at the funeral of his wife.

“I didn’t expect them to come, but they all did,” Perez said quietly as he stood on a soggy trail. “It meant a lot to me.”

Later on that afternoon, searchers returned to the center, tired and with boots caked in mud. Nothing had been found that could help bring Sierra home.

But as Marlene LaMar looked around the dining area, listening to the sound of laughter, she smiled.

Spirits, she said, are raised with every search.

“It’s inspirational to know that there’s still so much good out there.”

For more information about the search efforts, visit www.findsierralamar.com.