The district is named for Ebenezer Wood, an upstate New Yorker turned farmer who settled here in the mid-1800s. The debate over Wood Colony’s future has been complicated by Old German Baptist Brethren customs, which discourage political involvement, military service and voting. “We believe prayer goes a long way,” Mr. Wagner explained.

The group originated in what is now Germany in the early 18th century. In recent years, the 6,000 or so Old German Baptist Brethren living in the United States have struggled with encroaching urbanization and the loss of agriculture, said Gerald J. Mast, a communications professor at Bluffton University, a Mennonite college in Ohio, the state that is home to the country’s largest Old German Baptist Brethren population. Debates over alternative occupations and use of the Internet are continuing.

Despite the Brethren’s political neutrality, he said, some districts do countenance involvement in local issues, particularly in the West. “There is a deep streak of pragmatism,” Professor Mast said. “They are working hard at maintaining community, and they’re fairly savvy in going about it.”

In Modesto, Wood Colony residents, including the Old German Baptist Brethren and their allies, have shown up by the hundreds at City Council meetings, which have been the most contentious in recent memory. The Brethren “don’t speak up,” said William Heinrich, who was raised in the Brethren church but is now senior pastor at the Sovereign Grace Baptist Church. “Therefore it is our responsibility to speak up for them.”

The word “annexation” echoes through Wood Colony’s board-and-batten houses, many of which boast orange trees and stately palms. Carol Whiteside, a former mayor of Modesto and the founder of the Great Valley Center, a regional public-policy think tank, said that should the general plan amendment move forward, only a zoning change would be required for interested parties to sell off Wood Colony land for development. “These decisions are so easy to make 10 and 25 acres at a time,” she said. “People don’t look at the cumulative impact.”

Garrad Marsh, the current mayor, says that the city needs “shovel ready” land near major transportation thoroughfares to attract business. The agricultural designation proposed for Wood Colony is intended to protect it, he said. Yet many residents, he said, “perceive it as a ‘bait and switch.’ They are of the belief that any change is unacceptable.”