Urban exploration draws attention to Muirdale Sanatorium’s long transition into Milwaukee County’s Research Park

A former tuberculosis hospital now sits at the center of a modern business campus

Interest in “urban spelunking” and other forms of urban exploration has renewed public attention on one of the most distinctive surviving buildings on the Milwaukee County Grounds: the former Muirdale Tuberculosis Sanatorium in Wauwatosa, now incorporated into the Milwaukee County Research Park.

The Muirdale complex—centered on an Administration Building and a separate powerhouse along Innovation Drive—was completed in 1915 as a county facility created specifically to treat tuberculosis. The site’s design stood out from many early 20th-century sanatoria because key functions were consolidated in a tall, centralized building rather than spread across low cottages. Over time, additional structures were built on the surrounding campus; many of those smaller outbuildings and cottages no longer exist.

Why Muirdale mattered in public health history

Milwaukee County authorized the project in 1913 amid a period when tuberculosis was a leading cause of death and dedicated treatment infrastructure was limited. The building was designed by the architectural firm Robert A. Messmer & Brother, and was named for Wisconsin naturalist John Muir. In the mid-1930s, the main building was expanded upward to add capacity and operating space. At its peak, historical property records describe the facility as accommodating hundreds of patients.

As tuberculosis incidence declined following advances in medical treatment after World War II, the need for large-scale institutional care diminished. Muirdale ended its role as a tuberculosis treatment center in the late 1960s, and the site later took on other functions before closing in 1978.

Preservation, repurposing, and the research-park era

After years of uncertainty, the surviving buildings were preserved and ultimately incorporated into the Milwaukee County Research Park. The former sanatorium building became a key part of the campus’s business-incubator infrastructure, known as the Technology Innovation Center, which opened in 1993. The broader research park, established as a technology-oriented employment center adjacent to regional medical and academic institutions, grew through subsequent decades as land was developed and employers moved in.

In 2018, the Muirdale Tuberculosis Sanatorium’s surviving structures were added to the State Register of Historic Places and later listed in the National Register of Historic Places, formalizing their historic significance while allowing continued reuse.

What urban exploration raises—and what it does not settle

Urban exploration content often focuses on the tension between abandoned spaces and current redevelopment. In Muirdale’s case, the central facts are more complex: the site is both a preserved historic landmark and an active part of a working business campus. That combination creates practical boundaries for would-be explorers because access, safety, and property rules differ from truly abandoned sites.

• Muirdale’s remaining buildings are recognized for historic significance and are still in active use.
• Much of the original campus has been altered, with many smaller treatment cottages no longer standing.
• The site’s current identity is tied to economic development and entrepreneurship as well as its public-health past.

Muirdale’s story is not only about what remains of an early-1900s institution, but also about how Milwaukee County’s built environment has been repeatedly repurposed to meet changing public needs.

As public curiosity grows, the Muirdale site illustrates how local history can persist inside active redevelopment—where preservation, memory, and modern use share the same address.