7 Millie Mine Bat Viewing Site 
wildlife viewing |
directions and facility information
All bats have a sophisticated sonar system that allows
them to capture flying insects in total darkness.
Bats are very beneficial to humans, consuming thousands
of insects, many of them considered pests, every night.
The visible portion of this site is small and inconspicuous—just
the mouth of an abandoned iron ore mine that is covered
with a special steel grate. But what lies beneath
the surface is another story. A steep mine shaft drops
360 feet into the earth, providing a roosting and
hibernation chamber for bats. The mine entrance is
just a short walk from the site parking area. This
abandoned mine is just one of thousands that were
created in the upper peninsula throughout its rich
mining history. Mine shafts opened in search of iron,
gold, copper, and uranium. Many mine shafts have been
closed with rock, earth, even old car bodies, to reduce
their hazard to humans, but unfortunately, also destroying
their value to over-wintering bats. The special grate
on the Millie Mine prevents people from falling into
its vertical shaft, yet allows bats to come and go
as they please. This is one of about 30 sites that
have been protected with similar bat entrance grates
in the Upper Peninsula. It is the first one to be
developed as a bat interpretive site.
 Wildlife
Viewing
The Millie Mine is a critical hibernating and breeding
location for up to 50,000 bats—one of the largest
known concentrations of bats in the Midwest. Big brown
and little brown bats from all over the region come
here to hibernate during the cold winter months. They
are believed to migrate in from throughout the Great
Lakes region–Wisconsin, Minnesota, Ontario, perhaps
even Michigan’s Lower Peninsula. Bats start arriving
at the mine in late August and early September. They
remain in the mine shaft throughout the winter and
begin emerging in late April and May. Some use the
mine as their permanent home. Most, however, will
fly back to their forested home areas to spend the
summer where they roost during the day under the bark
of dead trees or in other small crevices. The females
will typically use large hollow trees, abandoned buildings,
or other human structures as maternity roost sites
where they raise their young with other females during
the summer. Males live a separate and more solitary
life during this time.
The best time to view bats is in September and early
October, right at dusk, as the bats begin to emerge
from the mine. They feed throughout the night and
return an hour to half hour before daylight. Local
businesses cooperated with the Department of Natural
Resources and its Nongame Wildlife Fund to erect the
steel cage over the top of this mine and to develop
it as a bat interpretive site. It has become an area
attraction, adding economic benefits to the Iron Mountain
area. The site has been host to a national bat festival
that is held annually throughout the country by Bat
Conservation International. The festival attracted
thousands of participants when held at this wildlife
viewing site. |
>Watchable
Wildlife
