L.A. County's Regional Planning Commission Celebrates 100 Years of Service

The first planning commissioners were appointed by the Board of Supervisors in 1923, making the Regional Planning Commission the oldest county planning commission in the United States.

2 minute read

April 25, 2023, 12:00 PM PDT

By Clement Lau


Vintage 1929 map of Los Angeles

County of Los Angeles / Map of Los Angeles, 1929.

In 2023, the Los Angeles County Regional Planning Commission (RPC) celebrates its 100th anniversary. In late 1922, the L.A. County Board of Supervisors created the Commission with staff to coordinate land use planning within the county. The first regional planning commissioners were appointed by the Board in early 1923. This makes the RPC the oldest county planning commission in the U.S.

The RPC acts as an advisory body to the Board of Supervisors on all planning matters. The commissioners administer provisions of the State Planning Law (Title 7, Division I, of the Government Code), the State Subdivision Map Act, California Environmental Quality Act, and the LA County ordinances affecting planning such as the County Zoning Ordinance and Subdivision Ordinance. They advise on planning policies and conduct regular public hearings and meetings. RPC consists of five Commissioners which are appointed to four-year terms by the Board of Supervisors.

To commemorate and celebrate this significant milestone, the Department of Regional Planning (DRP) created a StoryMap which summarizes the fascinating history and major accomplishments of the RPC and DRP. For example, the inaugural RPC immediately got to work on the issues of the day and started the development of a zoning code early on.  The Board of Supervisors adopted what became the first county zoning code in the nation on September 12, 1927. Following adoption of the zoning code, the RPC initiated the process of creating precise zoning plans for many unincorporated areas and places.

Friday, April 21, 2023 in Los Angeles County Department of Regional Planning

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Close-up of "Apartment for rent" sign in red text on black background in front of blurred building

Trump Administration Could Effectively End Housing Voucher Program

Federal officials are eyeing major cuts to the Section 8 program that helps millions of low-income households pay rent.

April 21, 2025 - Housing Wire

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

April 30, 2025 - Diana Ionescu

Ken Jennings stands in front of Snohomish County Community Transit bus.

Ken Jennings Launches Transit Web Series

The Jeopardy champ wants you to ride public transit.

April 20, 2025 - Streetsblog USA

Close-up of white panel at top of school bus with "100% electric" black text.

Driving Equity and Clean Air: California Invests in Greener School Transportation

California has awarded $500 million to fund 1,000 zero-emission school buses and chargers for educational agencies as part of its effort to reduce pollution, improve student health, and accelerate the transition to clean transportation.

6 hours ago - California Air Resources Board

Aerial view of Freeway Park cap park over I-5 interstate freeway in Seattle, Washington at night.

Congress Moves to End Reconnecting Communities and Related Grants

The House Transportation and Infrastructure Committee moved to rescind funding for the Neighborhood Equity and Access program, which funds highway removals, freeway caps, transit projects, pedestrian infrastructure, and more.

7 hours ago - Streetsblog USA

"No Thru Traffic - Open Streets Restaurants" sign in New York City during Covid-19 pandemic.

From Throughway to Public Space: Taking Back the American Street

How the Covid-19 pandemic taught us new ways to reclaim city streets from cars.

April 30 - Next City