"We thought we would pay our respects," said Purcell, who brought his twin 7-year-old sons, Shane and Kai.
"It's sad because we didn't get to see it alive," Kai said. "That poor calf has got to swim around for the rest of its life without its mother."
The calf swam back out to sea on July 23, about the right time for it to wean and go off on its own. But efforts to drive its mother back to sea with calls of killer whales played upriver and other measures did not persuade it to leave.
Instead it remained, sometimes feeding on invasive species of clams and snails in the mud of the river bottom, shooting great geysers of air and water out of her blowhole, and spending much of its time within sight of people who lined the U.S. Highway 101 bridge for the unusual show.
"It's very sad," said Thomas O'Rourke, chairman of the Yurok Tribe, whose reservation lines the banks of the river south of Crescent City, Calif. "It started to become a part of the community."
The whale died around 4 a.m. as it was observed by a number of scientists.
"Based on the photos and everything, her fat layer looks good, so we don't think she starved to death. There's something else going on," said Sarah Wilkin, a coordinator for the National Oceanic and Atmospheric Administration who was a member of the team studying the whale and urging it back to the Pacific.
Ashala Tylor, a freelance photographer, has been making pictures of the whale for weeks and said she saw it alive Monday night.
"I stayed until about 2 a.m. this morning and she was swimming around the bridge," Tylor said. "When I came back this morning she was on her side as dead as can be. I was shocked when I saw her."
Researchers took measurements of the dead whale, and the animal was expected to be buried later on the gravel riverbank during a private ceremony held by the Yurok Tribe among tall willows near the spot where it beached.
The last time wayward whales made headlines in California was in 2007, when a mother humpback and her calf journeyed 90 miles up the Sacramento River. The two whales were followed by crowds for more than two weeks before swimming back out to the Pacific Ocean at night.
O'Rourke visited the dead whale and said a prayer for its new journey. He believes it might have been showing its calf a place it had known in its youth.
"This is the farthest up river I have ever seen a whale," he said. "They come into the mouth regularly, the bottom end of the estuary. I believe there is a message there, and we are still yet to understand."