Lake Michigan is one of the five Great Lakes located in North America and does not have a connection to the ocean. Bull sharks require saltwater or brackish water to survive, and the lakes are freshwater bodies. Additionally, the water in Lake Michigan is generally too cold for bull sharks, which prefer warmer climates.
While there have been occasional unconfirmed sightings of bull sharks in the Great Lakes, these sightings are extremely rare and have not been substantiated with concrete evidence. Therefore, it is highly unlikely that bull sharks are found in Lake Michigan or any of the other Great Lakes.
Nonetheless, it is always essential to be aware of potential hazards when swimming or engaging in water activities in any environment, including the Great Lakes.