CEDAR RAPIDS — An archaeologist’s report evaluating large underground caverns believed to be long-forgotten beer caves — subterranean rooms brewers used for cooling and aging beer before refrigeration — underneath Interstate 380 in Cedar Rapids could take up to a month to complete.
That report by the Office of the State Archaeologist will be submitted to the Iowa Department of Transportation bridge office, which will then recommend a fate for the three to four caverns discovered during a routine bridge inspection of the Seventh and Eighth Street access ramps in late July.
“We don’t know yet about whether we would fill them in, but if we did, we’d we do it in a way that would preserve the archaeological integrity, such as with a type of sand or grout filling,” said Jim Schnoebelen, a DOT district engineer. “That’s the direction we are heading, but we don’t know for sure yet.”
In the meantime, the interstate and the access ramps above the caverns are safe, DOT officials said.
“The DOT does not believe there are any structural concerns at this time with the bridge or ramp,” said Cathy Cutler, a transportation planner for the District 6, Cedar Rapids office.
She added that the bridge is held up by steel pilings.
DOT staff and historians believe the caverns are remnants of a brewery that’s been closed for nearly a century. The brewery next to Cedar Lake in 1857 was best known as Magnus Brewing Co. and Eagle Brewery Co.
The caves, which were built into the hillside out of stone, are covered up and out of view.
Although thousands of motorists pass over them every day, they’d been largely forgotten in the decades since Iowa’s state prohibition rules in 1916, which were instituted in advance of federal prohibition in 1920. The brewery was demolished in the 1930s, but the caves remained to be built over by homes and then the interstate.
Cutler said they believe heavy rain this summer washed an opening in a grassy patch to this piece of history. She said the void is currently capped by plywood until they receive the archaeologist’s report.
The DOT hired the state archaeologist to confirm what is below the interstate. The archaeologist’s office will assemble its information into a report that will be submitted to the DOT bridge office in Ames,
The archaeologist’s office did not release many new details about its work on Friday, but did say they are deep in the investigation and will not be involved in any engineering or highway decisions.
“Our domain is to identify any historic properties that might be on their land,” said Carl Merry, the office’s highway archaeology program director, adding, “Our work is in progress and that is all I am going to say about it.”