Confusion Hill is now more than just an unusual roadside attraction.
The state Historical Resources Commission on Friday officially deemed the gravity-defying tourist stop in northern Mendocino County a California Point of Historical Interest.
"We're really happy," said Carol Campbell, who owns and runs Confusion Hill with her husband, Doug Campbell.
They're hoping the designation will help them overcome the Highway 101 bypass that removed them from the main road to Eureka.
They can now erect a sign at the Highway 101 offramp leading to the attraction located in Piercy, about 80 miles north of Ukiah and just south of the new highway bypass over the Eel River.
The bypass was built to avoid the chronic mudslides that regularly closed Highway 101 during the winter.
Doug Campbell applied for the point of historical interest designation in an effort to combat the loss of business because of the bypass.
The attraction was built in 1949 by George Hudson, who was inspired by other roadside oddities such as the Vortex in Oregon where tennis balls seem to roll uphill and brooms stand on end.
Inside the gravity house he built, people look and feel as though they need to lean to stay upright. Confusion Hill also features a narrow-gauge railroad ride and historic logging equipment.
It's notable as an example of a roadside attraction created to lure Americans who were increasingly buying new cars and taking advantage of new and improved highways to make road trips. It's also the only example of a gravity house in Mendocino County, according to a Historical Resources Commission staff report.
The commission also forwarded the nomination of the Jerome B. Ford house in Mendocino for placement in the the National Register of Historic Places, based on its place in lumber history.
The Register, a division of the National Parks Service, has 45 days to make a final determination on the designation, said state historian Jay Correia.
The house, which now belongs to the state, was built on the Mendocino bluffs overlooking the Big River estuary in 1854 by the California Lumber Manufacturing Company.
Ford, who was the company's manager, is credited with founding the first logging mill on the Mendocino Coast.