A TriMet driver is credited with rescuing a dog that had been taken by a stranger and brought onto a bus.

Mike Thomas was driving a Line 54 bus along Capitol Highway the night of March 9 when he encountered a man, holding a dog by the collar, standing in the middle of the road.

The car ahead of Thomas had veered into the oncoming lane to avoid the pair, and Thomas said stopping to let them board seemed the safest option. (Under normal circumstances, TriMet requires pets to be in a carrier and service dogs to be on a leash.)

The man started to board while leaving the dog in the street.

“I asked him, ‘Is that your dog?’ " Thomas said. "He said, ‘Yes, but he’s OK.’ I said, ‘No, you need to get your dog, he’s in the road.' "

The man called the dog, but not by name.

And the Labrador Retriever — friendly to every stranger it meets — climbed aboard with a tennis ball in his mouth.

Nothing about this situation seemed right to Thomas, who overheard the man talking to a woman on the bus and offering the dog to her. At one point, the dog walked close to the driver’s seat and Thomas saw a phone number and name on his collar name tag — “Cooper.”

When asked, the man could not give the dog’s name.

“Things didn’t fit together, so I let him know that I just wasn’t buying it,” Thomas said. “When I got downtown, the gentleman was going to exit,” — with the dog — “and I grabbed Cooper’s collar and informed him that Cooper would be staying with me, and that I would be getting him back to his family.”

Thomas called transit police, who asked if he wouldn’t mind keeping Cooper until they could catch up with him at the Washington Square Transit Center.

So Thomas kept Cooper on board, asking a regular rider whom Thomas knew if he wouldn’t mind keeping an eye on the pup. Surveillance footage released by TriMet shows the dog quite content, riding the bus for nearly an hour and making friends with the riders.

“He was very well behaved,” Thomas said. “Most of the time, he just had a tennis ball in his mouth, and he sat and just kind of watched everything going on and seemed like a really happy dog.”

Meanwhile, a TriMet dispatcher had called the number on Cooper’s collar and reached his owner, Jane Murphy, who happened to be out of town. Her son was checking on Cooper at their home in Southwest Portland. She had just learned from him that Cooper wasn’t in the house or in the backyard, when she got the call from TriMet’s dispatch center.

“They said your dog has been found, he’s on a TriMet bus,” she said.

Transit police delivered Cooper back home. When Murphy returned from her trip, she asked TriMet how she could thank the observant driver who had returned her dog.

On Thursday, TriMet arranged a meeting, where Thomas brought Cooper a bow-wrapped bone and Murphy got to finally thank Thomas in person for his help. Cooper, who just turned 4, has been part of the Murphy household since he was a puppy.

“I couldn’t imagine if that man hadn’t come on the bus, what he would have done with (Cooper,)” she said.

It’s unclear how the man came to have Cooper, or why he claimed the dog was his when Cooper had a name tag and a microchip. Murphy’s just grateful that in this case a TriMet driver went “the extra mile” to get her dog returned safely home.

-- Samantha Swindler / sswindler@oregonian.com