(PHOENIX) – The National Trust for Historic Preservation has designated two Arizona properties to the coveted America’s 11 Most Endangered Historic Places list. The May Hicks Curtis House in Flagstaff and the Mystery Castle in Phoenix were notified Wednesday.

"It may seem odd to celebrate the designation of a ‘Most Endangered Property,’ but these designations are highly coveted, as they come with the National Trust's resources to promote awareness about these unique, but imperiled, properties,” said Kathryn Leonard, State Historic Preservation Officer. “Arizona's previous ‘Most Endangered’ designations for the historic 9th Cavalry encampment at Camp Naco and the Osterman Gas Station in Peach Springs represent preservation success stories that brought Arizonans together to develop creative solutions for their preservation and future use. I look forward to working with the communities of Flagstaff and Phoenix as they plan for the next chapter of these buildings' stories."

Built in 1934-45 by Boyce Luther Gulley, Mystery Castle in Phoenix is an 18-room handmade structure that combines elements of folk art and organic architecture. Its location near South Mountain and use of elements from the Sonoran Desert make it a popular destination for decades. Read more about Mystery Castle on the National Trust’s site.

In Flagstaff, the May Hicks Curtis home was under threat of demolition. May Hicks Curtis sewed the first Arizona state flag in 1911, and the home is where she lived and worked for decades. The home was built in 1913 just off the original 1920s alignment of Route 66. According to the city of Flagstaff, relocating the home is the only way to prevent demolition, and the city has located a temporary property for that move, funded in part by a grant from the Preserve Route 66 Grant Fund of the National Trust for Historic Preservation.

The 11 Most Endangered Historic Places list brings greater awareness to places that are of historical significance that are at imminent risk of being lost forever if not preserved.

Since 1988, the National Trust for Historic Preservation has listed more than 300 sites on its 11 Most Endangered Historic Places annual list. Only a handful of those historic places that have been named have been lost, but for most, the listing is a turning point for renewed support for preservation efforts.

In 2022 and 2023, two other culturally significant locations in Arizona were named to the 11 Most Endangered Historic list by the National Trust for Historic Preservation: Camp Naco in Bisbee and the Osterman Gas Station in Peach Springs, Ariz. 

About Arizona State Parks and Trails

Arizona State Parks and Trails connects people to the outdoors and history of Arizona to build a lifetime of memories. For information about the more than 30 Arizona state parks and natural areas, the State Trail and Off-Highway Vehicle programs, and State Historic Preservation Office, call 1-877-MY-PARKS or visit AZStateParks.com.

About the National Trust for Historic Preservation

The National Trust for Historic Preservation, a privately funded nonprofit organization, works to save America’s historic places. www.savingplaces.org.