Some of the mines were opened in the 1840s and were closed and abandoned over 100 years ago. While many mine operators have taken precautions to fill in and secure abandoned mine areas, many old mines were opened and then abandoned long before any consideration was given for making the areas safe after ore extraction was completed. Michigan has many mines that were opened up in the 1840s. There are very limited records of the locations of shafts. Also it may not be known how near the surface these undermined areas are or how extensive the mine voids may be.
People enter abandoned mines for a variety of reasons, ranging from curiosity to vandalism.
Those who seek these pastimes often meet with sorrow and misfortune. Any old mine can be a death trap. Trespassers not only violate the law but they risk their lives and the lives of others. Probably the greatest number of accidents around mines occur to children. Public schools in mining districts should teach children about the dangers that exist around these old abandoned mines.