Ernie Carpenter, who stepped down 16 years ago from the Sonoma County Board of Supervisors, stunned the west county political community Thursday by jumping into the race for his former seat, now held by first-term incumbent Efren Carrillo.

Carpenter, 69, of Occidental, who was first elected to the board in 1980 and served 16 years, joins former Santa Rosa City Councilwoman Veronica Jacobi in trying to unseat Carrillo from his 5th District seat.

A strong environmental advocate, Carpenter said his move — made one day before the filing deadline — was partly based on dissatisfaction with Carrillo's record on land-use issues.

"I don't trust him on land use going into the future," Carpenter said, pointing to construction, real estate and development interests that continue to be some of Carrillo's chief campaign donors.

Last month, Carrillo, 30, reported $101,748 in available campaign cash, a formidable war chest to defend his seat, which represents most of the west county, including west Santa Rosa, Sebastopol, the Russian River corridor and the coast from Bodega Bay to Mendocino County.

Carpenter acknowledged the fundraising edge, the last-minute timing of his decision and the waves it caused in the west county as news spread Thursday.

"Everyone is shocked, there's no question about that," he said.

Carpenter, a former social worker, said he had been considering a run for at least six months and his decision was prompted in part by the long odds many give Jacobi in unseating Carrillo.

"When nobody appeared on the scene that I thought could beat Carrillo, I went into a whole other analysis," he said.

He cited Carrillo's support for several controversial projects, including his deciding vote in favor of the Dutra Materials asphalt plant south of Petaluma and, in the 5th District, his endorsement of the Best Family Winery project. It got unanimous board approval for a county general plan change that allowed a production facility, tasting room and vineyard on an apple orchard off Highway 116 and Occidental Road.

Also in question is Carrillo's stance on Preservation Ranch, the forest-to-vineyard conversion project on nearly 20,000 acres outside Annapolis.

Carrillo has refused to indicate his position on the controversial project, which is still under review. That uncertainty and the other development-related votes have led some in his district to push for his ouster.

Carrillo has defended his environmental record, citing his support for a large county purchase of open space on the Jenner Headlands, his backing of a proposed bid to form a county power agency to boost green energy development and and his leadership on a fisheries restoration grant program.

"The record speaks for itself," Carrillo said last month. "I believe I'm just as strong of an environmental advocate as most folks in this county."

He could not be reached for comment Thursday.

But Carpenter, who since his retirement from the board has worked as a consultant for local waste hauler North Bay Corp., called that record "lip service."

He said he had not talked with Carrillo about his decision. He described their relationship as "cordial but standoffish."

Carpenter's entrance into the race put west county political observers into overdrive Thursday. Some who have questioned Carrillo's politics welcomed the move.

"With Jacobi in, we had a challenger. With Ernie in, we have a race," said Dennis Rosatti, executive director of Sonoma County Conservation Action, the largest local environmental group. "

Rosatti said the group has interviewed Jacobi and Carrillo for an endorsement and now would make plans to interview Carpenter.

Jacobi, also a veteran environmentalist, expressed surprise at Carpenter's decision but said it would not change her campaign plans.

"I'm excited about it actually," she said. "I think Ernie is up to the task and I'm also up to the task."

In a brief interview, Carpenter also cited declining road maintenance, the county's fiscal challenges and concerns about maintaining strong land-use planning as playing into his decision to run.

"I'm very disturbed about the leadership in the county, particularly in the 5th District," he said. "I think we can do a heck of a lot better. I know I have a lot of experience."