Not only are they large whales, but they live a long time. The average fin whale lives more than 100 years.
Stinson is a world famous beach not far from where Sir Francis Drake supposedly first landed, but that's not what drew the crowds and the crowd watchers.
"People are curious about it. They want to look at it," one man said.
"I just saw a bunch of people and then the first thing my mom said was, 'there is a whale." bystander Amelia Rosenman said.
When the 42-foot-long endangered species fin whale washed ashore it was clearly in distress.
"It was still alive at 7 a.m. when I got here. It died about a quarter to 10. It made one last push to try and get offshore," Stinson Beach Fire Department Chief Kenny Stevens said.
After the whale died, attempts to haul its 30-ton carcass out of the water failed.
Even at less than a year old, the whale was just too heavy.
By then, the rescue operation had become one of disposal.
"If you take it out back in the water, it will wash up and be somebody else's problem," Stevens said.
When the tide went out, researchers from Marin County's Marine Mammal Center performed a necropsy on the whale.
Dr. Shawn Johnson and his team examined everything from the heart, lungs, thorax and stomach.
"If it was human related we want to find that reason, if it's disease we want to better understand what is affecting the populations of these endangered whales," Johnson said.
Only 3,200 fin whales remain along the Pacific Coast.
Officials plan to bury the endangered fin whale at the beach.