(CNN) -- June 4, 2010, was supposed to be just another day in second grade for Kyron Horman.
His stepmother told police that she'd dropped off the boy that morning at Skyline Elementary School in Portland, Oregon. But he hasn't been seen since he was spotted standing in front of his classroom's doorway, after having attended a science fair at the school.
Those 12 months have been trying not only for Horman's family, but also for the thousands of people -- many of them total strangers -- who have devoted their time, effort and prayers in hopes of finding Kyron.
"Every day that goes by is harder," said Jude Maher, a local volunteer leader who has kept in contact with Kyron's biological parents, on Saturday. "But the one thing that I've learned is that you never give up hope."
Most of the speculation has focused on the boy's stepmother, Terri Horman. In August, investigators solicited the public's help for information about the location of the white pickup truck that she is believed to have driven the morning of then-7-year-old Kyron's disappearance.
And in divorce filings, the boy's father, Kaine Horman, said he believes Terri Horman "is involved" in the boy's disappearance. Court documents also allege Terri Horman tried to hire a man to kill her estranged husband.
But no charges have been filed against anyone in the case, nor has anyone officially been named as a suspect -- including Terri Horman.
This is all despite a substantial effort, not only by volunteers like Maher, but also law enforcement agencies.
The Multnomah County Sheriff's Office said in a press release Thursday that its deputies working with the FBI, Oregon State Police and five other law enforcement agencies have compiled 68, 4-inch-thick binders of material exclusively on Kyron's case. Investigators have tracked more than 4,500 leads and conducted more than 3,500 interviews.
In total, the sheriff's office estimated that investigators had spent more than 26,650 hours on the case, which is just over the roughly 24,640 hours that the county's search and rescue coordinators and volunteers have spent looking for the boy.
While they are professionals, the hunt has taken its toll, Multnomah County Lt. Mary Lindstrand said late last October.
"There is an emotional trauma to going out and searching for a child," Lindstrand said. "A child is gone. The pain of that is so terrible that the searchers begin to feel it physically. You just keep looking, no matter what."
For the second time since going from 10 to eight deputies dedicated to the case in September, the sheriff's office this week announced a significant tactical shift. Effective July 1, four law enforcement agencies (half the current eight) will be involved in an investigation that will focus more on "technology-based forensics, data entry and review of information compiled."
Already, the case has prompted technological changes at Kyron's school, where video cameras were installed to show the outside of the building and the main hallyway. In a letter to parents, Principal Ben Keefer also said that security procedures would be reviewed to ensure they are effective.
Another significant development has been how the community has responded.
"When Kyron first went missing, the whole state was in shock," Maher said. "We just don't have things like that happen in Oregon. The response was amazing."
Beth Greear organized a candlelight vigil for Kyron in July. Expecting 40 or so people, she said that nearly 300 showed up. Since then, there have been fund-raisers, public awareness events and the creation of a "Wall of Hope" -- a chain-link fence now outside a local fire station that features an assortment of personal messages, pictures and trinkets. Among them are an array of frogs inspired by Kyron's project of red-eyed tree frogs that he did for the science fair the day he went missing.
Maher, who lives in Wilsonville, said she got involved the day after the news broke, trying to help in any way she can. She and others have since devoted scores of hours to the cause.
"I'm not a family member. I'm just ... a mother, I'm a volunteer, I'm someone who fell in love with a little boy," she said, adding that many others felt a similar draw to Kyron.
Maher and Greear have plenty of company, be they searchers from around the Pacific Northwest or online supporters from as far away as India. A post office box, which Greear set up for the cause and goes to the Horman family, has received mail from the Netherlands, New Zealand, China and beyond.
Within days of creating a Facebook page titled "Missing Kyron Horman," Maher said 19,000 signed up. By Saturday, the one-year anniversary of the day he went missing, that number had soared past 87,700 -- posting notices, prayers, words of support and occasional allegations about those they feel are behind the boy's disappearance.
"My heart is crying out for your safe journey home," wrote Ann Pechulis from New England. "We imagine you have grown taller and some features have changed, but we will recognize your beautiful smile when (we see) you!"
Those people have helped spread the word, with one commenter noting that fliers with Kyron's face "are all over Tacoma and Seattle." The FBI's announcement asks for people to look out for the brown-haired, blue-eyed boy -- who weighed 50 pounds and stood 3 feet, 8 inches tall when he was last seen -- to contact a nearby FBI office or U.S. embassy or consulate, should they spy him abroad.
The boy's biological parents have also made a number of public appearances, including an event held on September 9 to mark Kyron's eighth birthday. On Saturday, Kyron's father, Kaine Horman, joined scores of volunteers working to beautify the grounds outside Skyline Elementary.
And in recent weeks, billboards have sprouted up anew featuring Kyron and urging people to call 503-261-2847 with tips for police.
One such billboard in Roseburg, about 180 miles south of Portland (where Terri Horman is believed to live), shows several pictures of the boy and the words, "I promise I will find you. I will never stop" -- a message from "Momma," Kyron's biological mother Desiree Young.
Saturday's spurt in online activity, the new billboards and fresh mementos at the "Wall of Hope" attest to the fact that time has not diminished volunteers' desire to find Kyron.
Still, Greear admits that staying optimistic is a growing challenge, absent any new developments or indications about the boy's whereabouts.
"We're all trying our best to keep that hope alive," she said.
In a statement released to the media Friday, including to CNN affiliates KGW and KOIN, Desiree Young acknowledged how "heartbreaking" the past year has been, saddled by "our sense of loss and the senselessness of this act." Yet she said that she has been buoyed by the tremendous outpouring of support from law enforcement, relatives, volunteers and others.
"My belief in the goodness in people and the strength of hearts everywhere has been restored," Kyron's mother wrote. "I believe that is what will bring Kyron home to us, the goodness in people."
CNN contributor Bob Greene contributed to this report.