Some of our first experiences with death and dying often come when we lose our childhood pet. For many of us, animals become part of the family -- faithful companions who are missed deeply when they're gone. How we remember our pets can say a lot about who we are as humans, too.

In the foothills above California's Napa Valley is the Bubbling Well Pet Memorial Park. Founded more than 40 years ago, these five tranquil acres contain the remains and memories of some 12,000 pets -- dogs, cats, rabbits, ferrets and more -- who asked little in return for their loyalty.

The story of Bubbling Well's creation was told in Errol Morris' classic 1978 documentary, "Gates of Heaven" (left).

Dan Harberts (with Drake), who now owns the park, is reminded each day of the unshakable bond between animals and the people they leave behind.

He agreed that while people bury people because they have to, they bury pets because they want to. "It's so true," said Harberts. "You're doing it from pure love, and that's the highest form that we can pay tribute to, as far as our pets go."

Left: A statue of St. Francis of Assisi, patron saint of animals.

There are now more than 750 pet cemeteries nationwide, and in many (like here), the graves are attended to with care that's sometimes not afforded human cemeteries.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

Harberts thinks of the countless people he's met over the years, grieving a loss, and asking the same question many pet owners do: Where do they go when they're gone?

"I think whatever presence that we have in the afterlife is shared by everything, by all living creatures in some capacity," he told Cowan. "It would be important for me to have that as part of my afterlife."

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

A view at Bubbling Well Pet Memorial Park.

Helen Chulik, who regularly visits the grave of her dog, Fancy, believes, "we'll get together," she told Cowan.

"If there's a heaven, our pets will be with us, there's no doubt."

For more info:

Bubbling Well Pet Memorial Park, Napa., Calif.

International Association of Pet Cemeteries and Crematories

"Gates of Heaven" by Errol Morris (errolmorris.com)

By CBSNews.com senior producer David Morgan