Milwaukee’s Mitchell Park Domes named newest National Treasure

The beehive-shaped Mitchell Park Domes in Milwaukee have been called a lot of things during their 50 years of existence, from oases from the midwest winter to architectural oddities to “glass bubbles.” And now, thanks to the National Trust for Historic Preservation, they’re being called a National Treasure.

Announced earlier this morning, this designation comes with a new engineering report, commissioned by the National Trust, that offers a potential solution to the vexing problem of preserving these one-of-a kind structures.

Officially known as the Mitchell Park Horticultural Conservatory, the Domes have long been one of the city’s most eccentric structures, as well as a prime example of adventurous engineering and midcentury design. Local architect Donald L. Grieb’s conoidal-shape design, which called for a lace-like structure of concrete and glass cladding, won a national competition in 1958 (the inventive architect, seized with the idea for the Domes while asleep, reportedly woke up and immediately constructed a model out of balsa wood and toothpicks at home).

Due to the complex structural system—cast-in-place concrete undercarriages topped with a layer of steel and glass—the Domes took nearly a decade to complete. When they opened in 1967, the structures were heralded as a new landmark, “adventurous structures that remain unique in the world,” according to the Milwaukee Journal Sentinel. More than 600,000 flocked to tour the domes in their first year.

Library of Congress

The domes’s unique construction and design have proven to be a liability over time, as maintenance and upkeep have proven challenging ( a piece of concrete fell from one of the domes last February, temporarily closing the entire complex). Milwaukee County, which owns the buildings, has recently considered demolishing one of more Domes along with partial or full reconstruction, a stance that earned the structure a spot on the National Trust’s List of last year’s most endangered buildings.

The Trust’s report, part of the group’s work with the Milwaukee Preservation Alliance, outlines a $18.6 million rehabilitation program to restore the Domes. This plan costs roughly a third of the more elaborate rehab approach offered to the country last December by by engineering firm GRAEF Consulting.