In Michigan, the number of fishing lines you can troll with is determined by state regulations. The specific rules and limits may vary depending on the type of fishing you are doing. It's important to consult the Michigan Department of Natural Resources or the local fishing authorities for the most up-to-date information on trolling regulations. By following the guidelines provided, you can ensure you are abiding by the law and enjoying your fishing experience responsibly. Stay informed and be aware of any changes in the regulations to enjoy trolling in Michigan legally and responsibly.