Under a pall of gray clouds and cutting winds last Thursday morning, a crowd of misty-eyed stalwarts bid farewell to Drakes Bay Oyster Company as the farm shut down its cannery and retail shop for the last time.

The group of supporters struggled with a fraught mix of emotions: anger, sadness and honor, as John Wick of Marin Carbon Project put it. The day was a celebration of an oyster farm’s legacy that for many was cut unnecessarily short. A memorial and a funeral, Mr. Wick said.

“Today brings many historical changes to Point Reyes,” said Ginny Cummings, one of the farm’s manager and Kevin Lunny’s sister, as she held back tears. “The oyster farm’s teachings to visitors and classes of all ages on sustainable agriculture and how working landscapes can complement working ecosystems is over. The original mission of Point Reyes to demonstrate how the culture of our farms and ranches and our natural wilderness can coexist as a model of sustainability is over in Drakes Estero. California’s last oyster cannery is gone.”

Many of the morning’s speeches focused on a renewed commitment to former Interior Secretary Ken Salazar’s pledge in his Nov. 2012 decision to “support the continued presence of dairy and beef ranching” in the seashore. Albert Straus, who converted his family’s farm into the first organic dairy in California, pointed to the park’s elimination of farm worker housing and jobs.

“My family’s support for the park’s formation was because it took the farms as a basis for the existence of this land that has been sustainably farmed for over 150 years. This chapter might be over, but the battle to keep our farming community intact continues,” Mr. Straus said. “The farms in this park are threatened. Both the National Park Service and the farms must work together to continue to make this an example of how farms can be sustainable and viable in our community.”

Kevin and Nancy Lunny thanked the semi-circle of supporters for their dedication to the cause. They proposed a toast to the “hundred-year operation” and a “day to remain together and to effect change” with a fresh oyster on the half-shell. The farm’s production manager Jorge Mata lifted his oyster and said, “Salud!” and everyone downed their bivavles.

“This would have been the hardest day of our lives, but you’ve made it possible to see the brightness,” Mr. Lunny told the crowd as a lone bagpiper began to play.

Later in the day, a handful of last-minute visitors and news cameras lingered near the shack’s doors, watching the line dwindle. They wanted to be there for the very end. 

Employees still bustled with a job to do. “We still have everybody working,” Mr. Lunny said this week. “We’re keeping busy so we don’t have to lay anyone off, but it’s coming. Obviously without shucking and packing and without retail, it’s inevitable.”

A heavy-duty vehicle was parked by the shipping container that had served the oyster cannery, ready to lift the steel box off to temporary storage. 

“It’s really sad,” said Elizabeth Candelario, a Healdsburg resident and self-declared “serious oyster eater,” who was the last customer to ever buy a plate of a dozen shucked oysters and enjoy them at the picnic tables. “I understand the environmental point of view, but then I also understand the point of view of this business. It’s ironic because they’ve been so good from an environmental standpoint. I sure have appreciated them.”

At 4:29 p.m. Andrea Peroni, a Forest Knolls resident who worked in the shop with her daughter Erica, asked, “Anyone else need help?” One more woman took home a bag of shells on ice. It was time to close. “Do we really want to close the doors?” Ms. Cummings asked.

“I think we just walk way with the doors open because we’re leaving it open for all possibilities,” said Loretta Murphy, a  manager for the farm. “We close the doors and it closes. I say, leave it open. Leave it open.”

“Let’s hope we can call you back,” Ms. Cummings told them, “and say, ‘Hey, we need ya.’” The retail ladies and shucking gals all stood outside in a loose group hug, not wanting the moment—or the era—to end.