Rule 3. Removal of overburden and extraction of limited amounts of materials is not open-pit mining when done only for the purpose of exploration and to the extent necessary to determine the location, quantity, or quality of a mineral deposit. If the disturbed land does not become a part of a mining operation within 2 years, the operator shall grade and revegetate within practical limitations and in a manner acceptable to the supervisor.
Mich. Admin. Code R. 425.3