Flash Flood Roars through Bannack State Park

Annual Bannack Days celebration cancelled
Bannack State Park Assistant Manager Tom Lowe looks over the flood damage at Bannack last Thursday morning. A flash flood Wednesday evening did extensive damage to the site of Montana’s first territorial capitol. At Lowe’s left, is the former location of the Assay Office, a building sept away by the flood.
In this photo snapped by Bannack State Park Assistant Manager Tom Lowe, flood waters began receding after roaring through Bannack last Wednesday evening. Lowe took the picture shortly after the flash flood raced through town from Hangman’s Gulch.


A brief, fierce storm last Wednesday night north of Bannack created a flash flood that lasted a short time but left devastation that could take years to correct.  The damage, just three days ahead of the Bannack Days celebration which attracts over 5,000 visitors for the weekend to the site of Montana’s first territorial capitol, resulted in the immediate cancelation of the event and closure of the state park.

“An incredible amount of water came down Hangman’s Gulch,” said Bannack State Park Assistant Manager Tom Lowe.  “It was a major flooding event.”

According to Lowe, the storm hit at about 4:15 p.m. last Wednesday night, and the ensuing flooding raced through town, but quickly subsided.  There were 20 visitors in town and four were treated for minor injuries.

“Thank goodness it did not occur during Bannack Days,” said Lowe.  “If it had happened Saturday afternoon (it) would have been tragic.  Bannack Days is a fun event, but in the greater scheme of things, not that big of deal.  The damage to this beautiful treasure, Bannack, is what we’re really concerned about.  We’ve got to get it back together and do it right and its going to take some time.”

The damage included the destruction of the historic Assay Office, a building at the opening of Hangman’s Gulch where the flood waters poured through the center of town.  The remains of the building were piled across the street and down a hill. 

According to Lowe, the underground fire detection and fire suppression systems were filled with mud, the electrical transformers are all underground and filled with mud, artifacts were carried away and will have to be extracted from the mud and salvaged, the buildings are all filled with mud creating concerns of eventual mold damage.  Lowe added that boardwalks up and down the main street have been swept away and piled here and there, the visitor center well has been contaminated, and the porch on the Ovitt Store is clearly damaged.

Lowe feels there is the potential for major foundation damage on buildings that were in the direct path of the major flood activity.

According to Lowe, a weather station just south of Bannack on Old Stage Road recording .78 inches of precipitation, but he said the heavy rains fell north of Bannack and then ran down through Hangman’s Gulch into the center of town before running into Grasshopper Creek.

“It came down fast,” said Lowe.  “The hail was piled over a foot deep in places.  It was a devasting flood event but Bannack has been here for 151 years and hopefully it will be here for another 151 years.  We’ll recover.”