The Idyllwild Historic Downtown District (IHDD) is a preservation district established in 2011 by the Riverside County Board of Supervisors as Resolution 2011-178. Pursuant to Ordinance 578, the Board of Supervisors may approve the establishment of a Historic Preservation District. The purpose of creating the IHDD was to safeguard the historic look and feel of downtown Idyllwild, which attracts thousands of tourists every year and provides economic stimulus to the area's businesses.

The IHDD encompasses 152 properties located in the downtown area of Idyllwild and includes businesses and private homes whose architectural style and history embody the unique significance of Idyllwild as the County's earliest and most distinct mountain resort.

Like a zoning overlay, the IHDD provides an additional layer of review during the project review process when building permits are filed. Conducted by the LOCAL REVIEW BOARD, which is made up of five area residents, this additional layer of review ensures that changes to important buildings within the IHDD do not detract from the historic look and feel of the district as a whole.

When a property owner within the IHDD files a building permit with Riverside County Building and Safety, a building official evaluates whether the IHDD Local Review Board needs to review the project. If the project involves more than routine maintenance and the property in question, is one of the CONTRIBUTING PROPERTIES of the IHDD, the project will need to undergo this additional review by the Local Review Board. Utilizing established DESIGN GUIDELINES, the Local Review Board will work with the property owner to ensure all changes to the property preserve its historic look and feel.