"We have two types of Eagles here in Minnesota that we can see, the golden eagle just in the winter time in south east Minnesota and then the bald eagle throughout the summertime and the winter time as well," said Scott Mehus, an educator at the National Eagle Center. "We came very close to losing this bird. From Wabasha, where we are right now, all the way down the mighty Mississippi river to Rock Island Illinois, a distance of 261 miles, between 1968-1972 there was only one nesting pair of bald eagles left on that entire stretch of river. Unfortunately we introduced a chemical called DDT after WWII, and it did a wonderful job of getting rid of mosquitos and bugs so we wouldn't have malaria outbreaks, and the creators of that product didn't think it was going to do this, but the chemicals built up in the food chain and it affected the eagles and the females ability to process calcium and that caused the eggshells to become so thin that when the female, or male, went to incubate their own eggs they were often crushing them under their own weight, and that's why we came so close to losing the eagle. There was a time when people would come from Rochester, or Austin, or Albert Lea, the Twin Cities, and come to Wabasha here to see an eagle because they thought it might be the last eagle that they'd ever get to see. Thankfully we removed DDT from North America and the eagle numbers have been coming back ever since. In fact that same stretch of river today has more than 313 nesting pairs of bald eagles."Since DDT was banned in 1972, the number of nesting pairs of bald eagles nationwide has grown from just 487 before the ban to nearly 10,000 in 2006. States decided the progress was significant enough to stop keeping a yearly tally.