For safety reasons, some adits are closed completely with expandable insulation material.
Other adits are fitted with "bat gates" to maintain the bat habitat but make the hills safe for the curious explorer. Here Eve Byron, a reporter with the Helena Independent Record, takes a closer look at a bat gate installed in the Scratchgravel Hills north of Helena.
The Scratchgravel Hills north of Helena are surrounded by subdivisions, which means a dramatic increase in all types of uses over the last 20 years. The hills were named because prospectors would literally “scratch gravel” looking for gold and other minerals.
As use increased, the BLM recognized that many of the former mine features are attractive nuisances to visitors in the area and are accidents waiting to happen.
Joan Gabelman, Butte Field Office geologist, has spent a portion of the last several years identifying hazardous sites and trying to eliminate the danger without losing the historic or cultural values. Additionally, several of the adits and shafts have attracted bats over the years and are now wildlife habitat. Consequently, Gabelman has worked with other program areas including wildlife, cultural, geology and botany to determine the best course of action for each site.
Mitigation can come in a number of ways – some of the adits are closed completely while others have bat gates installed so that bats and other small critters can pass through but curious people are kept out. For other features, it is simply a matter of reshaping the tailings pile to make the area less hazardous.
Besides the obvious dangers, some adits have been known to contain old mining supplies such as dynamite or blasting caps. As they age, the explosive material crystallizes, making them more unstable – one more reason to address the issue.
Gabelman is quick to give credit to the state and national abandoned mine land programs for their funding and staffing support. She also likes to point out that the goal is to make the area safe for public land visitors -- not to erase history.
“We have such a rich mining history in western Montana,” said Gabelman. “We want to preserve as much as possible for future generations.”