Ten times a year for nearly a decade, Mel headed out in any kind of weather and over all types of terrain to look for missing people.

"She was motivated entirely by social drive. She wanted to find the lost person and return him to the pack. And all she wanted when she did was to have her butt scratched and someone to tell her she was a good dog," said Heather Houlahan, of Cranberry, owner of the German shepherd dog that was trained for search and rescue missions with the Allegheny Mountain Rescue Group.

On her very first mission, Mel, then a 1 1/2-year-old bundle of energy, was sent to help search for an elderly man missing from a nursing home.

Not only did Mel locate the man, but she didn't want to leave his side. She wagged her tail and licked him and later hopped into the ambulance that was transporting him.

"She was so sweet, and sweetness was not a job requirement," Ms. Houlahan said. "Mel was a part of this community in a way an ordinary pet doesn't get to be."

Mel died last Thursday. She was 13 years old.

One of her last rescue missions was featured in a best-selling anthology titled "Dog Is My Co-Pilot: Great Writers on the World's Oldest Friendship."

That rescue involved a 12-year-old boy with developmental delays who had been missing for several days in October 2001 in West Virginia.

Mel climbed a mammoth stack of hay bales in a neighbor's outbuilding and found the boy hiding inside.

In 2004, Mel was the subject of a Post-Gazette story when Ms. Houlahan issued a public plea for use of a swimming pool so that Mel could do rehabilitation exercises following surgery.

After rebounding from the life-threatening spinal problem, Mel returned to work at an age when most search-and-rescue dogs are retiring.

Two years before, Mel's abilities were showcased when debris from a demolished building was left at Cranberry's maintenance yard so that rescue dogs from five states could practice their work there.

Mel quickly detected a scent within the pile and ran to her owner, whining to signal a person was hidden at that spot. To test the dog's persistence, Ms. Houlahan sent the dog back to the rubble. Mel didn't give up. She sniffed the same place again and returned to her owner, continuing to whine until the hidden person was found.

The dog then continued working and found another person hiding in two overturned construction barrels.

"Mel" was short for Melian, a character from J.R. Tolkien's "Lord of the Rings" trilogy who was known for great wisdom.

But Ms. Houlahan said Mel didn't get off to the most auspicious start when she acquired the 7-week-old dog.

"It was a hopeful, hopeful name. She was hell on wheels at first," Ms. Houlahan said.

In what seemed to be a constant search for food, Mel learned to unzip backpacks and unscrew the lids of peanut butter jars. She also had a propensity for chasing deer that made Ms. Houlahan wonder whether Mel could learn to stay on task for search missions.

But with persistent training, Mel was able to focus her 70 pounds of agility, confidence and energy to become a top-notch search and rescue dog.

In addition to the volunteer search-and-rescue work, Mel assisted Ms. Houlahan in her work at Lap Wolf Dog Training, teaching other dogs to follow commands.

Ms. Houlahan said Mel was especially good at socializing dogs who were aggressive with other canines.