With 800 volunteers, 95 staffers, a $6 million budget and a sprawling Novato compound, the Marin Humane Society has come a long way from its humble beginnings in a San Rafael livery stable.

The venerable organization is celebrating its 100th birthday this year.

Its evolution to a nationally-recognized leader in animal training and the adoption of stray pets has taken it from a simple animal-lovers' philanthropy to a well-known and sometimes controversial animal activist organization with a lucrative $2.7 million animal control contract.

Founded in 1907 by San Anselmo native Ethel Tompkins, the formation of the Marin County Humane Society made it one of the first local charitable organizations as well as one of the first humane societies in the United States.

"The horse was the major mode of transportation - the extent to which horses were considered just that was of concern," said Diane Allevato, the society's executive director. "Much of the early work was less about sheltering companion animals and more about public education of overworking horses and the movement of cattle."

The organization set up shop in the Nevada Stables on Petaluma now Lincoln Avenue in San Rafael. Tompkins had kennels built and opened her San Anselmo home to the society's stray dogs and cats. In 1927, the group moved to 812 Third St. The society purchased the property in 1929.

The opening of the Golden Gate Bridge in 1937 brought people and pets. The society struggled to make ends meet and pay its lone officer, Scott Tilden. By the end of World War II, animal control was needed in Marin.

The society in 1946 took on the controversial task, despite objections from some who believed the society should stay out of the pound-keeping business.

"The society was very concerned that public funds would go toward opening a really dismal place with no hope," Allevato said.

The Third Street facility was expanded to accommodate the society's new role. In 1963, the group purchased the land that is now its headquarters on Bel Marin Keys Boulevard in Novato. The shelter there opened in 1968.

The complex was envisioned as an education center as well as a shelter and animal control facility, a revolutionary concept at the time spearheaded by the group's first executive director, Mel Morse.

Also cutting-edge was the sterilization of pets, a practice that took hold in earnest in 1973 with the construction of the society's spay and neuter clinic.

"Over-population was absolutely gruesome in the '70s," Allevato said. "There were thousands and thousands of kittens and puppies."

The first of its kind in California, the clinic was controversial because it was considered competition for pet hospitals. It was ladies first at the clinic - neutering was later added and contributed heavily to successful population control, Allevato said.

On her second day on the job in 1980, Allevato instituted neutering across the board.

"It immediately began having some impact," she said.

Sterilizing pets today is common practice, but it wasn't always that way, she said.

"It's like Mothers Against Drunk Driving," Allevato said. "They have done this phenomenal job of making this socially unacceptable, not just bad form but morally reprehensible.

"It's just not being a good citizen and it's also damn inconvenient and a nuisance to have your animal unsterilized."

Today the Marin Humane Society routinely accepts animals from across the state from shelters that would otherwise be forced to euthanize. The society enjoys the status of an "open-door" shelter, which means it is not forced to euthanize healthy adoptable pets due to overpopulation.

Marin Humane Society board president Suzanne Golt said that, in addition to a wide variety of programs and training opportunities for Marin residents, one of the society's greatest achievements is getting the public on board to fix Fido.

"The community has gotten the message," she said. "They are responsible."

Still, the movement has a ways to go, Allevato noted. Nationally, sterilization has yet to completely take hold.

Educational challenges exist in Marin as well. Whether its interactions with coyotes or frustration over braying or crowing creatures, Marin residents struggle to live harmoniously with the animals, Allevato said.

"There is a direct correlation, not between class and economic status but between education and how we deal with wildlife," she said. "Marin has a fairly high basic educational level - the concept of caretaker of the environment instead of a user of the environment - and I think that has a real impact on the values people have about companion animals, but we see conflicts."

Allevato, like her predecessor Morse, has never shied from controversy. Over the years the group has sparred with dairy ranchers, pet supply store proprietors and local Rotarians.

Novato attorney George Silvestri, former deputy county counsel, has for years raised objections to the organization's dual role as advocate and regulator - one of just a handful of such arrangements in the state. Silvestri clashed with society officials in 1997 over plans to host a Rotary Club-sponsored circus.

"My strong concern that evolved from that experience when we put on that circus for the Rotary is that they blurred the line," said Silvestri, who was president of the Rotary Club of Novato Sunrise at the time. "They were using their police power and their governmental authority to carry out their political agenda way beyond the scope of those ordinances.

"That's something I have yet to see someone take a close look at," he said. "Marin County prides itself on challenging government - why should they get a free pass?"

Allevato is retiring in July, but it is expected her successor will continue the society's long-standing tradition of animal activism.

"We will look for the next executive director to be every bit as active in animal activist issues that are appropriate," Golt said.

"I don't see the society's commitment to speaking on behalf of animals changing at all," Allevato said. "Essentially the message is going to be the same. If not us, who? We are the Marin Humane Society. We represent animals. Who is going to speak on their behalf? Whenever there's a human or economic interest, that's when the humane society says 'Let's take a look at what's happening here.' This is where somebody has to represent the animals.

"We're fairly ambitious," Allevato said. "We want to have a profound impact on the way society views animals.

"That's who we are and we're not going to cease being that."