L.A. County Completes Altadena Historic District, Its First, in Neighborhood Straddling Pasadena Line

The Los Angeles County Board of Supervisors on Tuesday took the final administrative step to establish the County’s first-ever historic district, formally creating the Historic Highlands Historic District in Altadena after the completion of legal review by County Counsel.

The ordinance creates a district of 77 parcels of early-20th-century homes in the unincorporated, northern portion of a neighborhood whose southern half lies within the City of Pasadena. The designation becomes effective July 9, 2026, and follows recommendations from the Historical Landmarks and Records Commission and the Regional Planning Commission, as well as what the Historic Highland Neighborhood Association describes as eight years of advocacy.

The Board first approved the underlying ordinance on July 22, 2025. Tuesday’s action, taken after County Counsel completed legal review and due diligence, makes the designation final.

The ordinance amends Title 22 of the Los Angeles County Code — the County’s planning and zoning law — to recognize the new district. The northern portion of the Historic Highlands is unincorporated and falls within Fifth District Supervisor Kathryn Barger’s jurisdiction. The southern portion of the same neighborhood is inside Pasadena city limits and is governed by the City.

“Today’s action marks the completion of a significant effort to formally recognize and protect one of Altadena’s most historically significant neighborhoods,” Barger said in a statement issued by her office. “With the County Counsel’s review now complete and the ordinance approved, we have taken the final step necessary to preserve the Historic Highlands’ unique character and architectural heritage for future generations.”

The district takes in homes built in Craftsman, Spanish Colonial Revival, Tudor, and other period styles, according to the Supervisor’s office. The press release described the neighborhood as developed during the 1920s from subdivided former orange groves.

More than 50 percent of affected property owners supported the designation, according to the Supervisor’s office. The County said the new district establishes guidelines that protect defining architectural features while continuing to allow appropriate property improvements.

The Historic Highland Neighborhood Association, the community group whose application prompted the County process, said the milestone followed “eight years of dedicated community engagement, including webinars, neighborhood meetings and outreach efforts.” The association said the new district includes 77 homes on the Altadena side, “with the southern portion governed by the City of Pasadena.”

The action arrives as Altadena continues to rebuild from the Eaton Fire, which broke out on January 7, 2025. Cal Fire reported the fire destroyed 9,418 structures. The Supervisor’s office said the Historic Highlands was not impacted by the fire.

“The Eaton Fire changed Altadena forever, destroying thousands of structures and dramatically altering parts of our community,” Barger said in the statement. “Preserving neighborhoods like the Historic Highlands helps maintain the sense of place that makes Altadena special. As residents rebuild and recover, these historic homes serve as a reminder of our community’s resilience and enduring identity.”

After the July 9 effective date, the district will be entered into the County Register and affected property owners will be formally notified, the Supervisor’s office said. The designation does not extend across the city line, and Pasadena property owners on the southern side of the Historic Highlands will continue to fall under City of Pasadena planning rules.