Michigan blueberries are the healthy finished product of North America's "Fruitbelt", where the shores of Lake Michigan provide an ideal equation:
temperature moderation [not too hot x not too cold] + frequent rainfall + rich soil + trees = an abundance of tasty produce
This is why Michigan is the leading producer of blueberries; perfectly positioned to supply nearby populations with the highest quality, most flavorful pick of the season. When buying local is possible, it's economical, delicious, and good for you, too.