🔍 Key Concepts

• Ice conditions and freezing patterns on each of the Great Lakes • How latitude and depth affect how long a lake stays frozen • Typical opening and closing dates of the commercial navigation season on the Great Lakes

💭 Think About

• Which lake is farthest north and tends to stay colder for longer periods each year? • How does deeper, colder water influence how long ice remains compared to shallower, more southern lakes? • Think about where most winter icebreaking operations and late-season closures are most frequently reported.

✅ Before You Answer

• Verify which lake is most northern and coldest overall • Consider which lakes are shallower and farther south, leading to longer ice‑free periods • Eliminate any lakes that are known for relatively mild winter conditions compared to the others