Think back 25 or 30 years.  Chances are, you might remember what city boulevards looked like then - with their towering Elm trees that formed a canopy over the street.  In their prime, the Elm Tree was the choice for boulevard trees;   They created a nice shady cover that let just enough light through their leaves.

Then - somewhere in the mid to late 1970's, Dutch Elm disease ran it's course through the United States, leaving the Elm Tree almost non-existent today.

That's why researchers are so interested in a forest in located in Kandiyohi, Minnesota.  On a 150 acre plot, the woods are thick with Elm Trees and they appear to be disease-resistant for the most part.

"It takes your breath away," said Mark Stennes, a plant pathologist specializing in Dutch elm disease. "There've been some losses, but it's an extraordinarily unusual phenomenon that those trees aren't gone. It's almost like it's a minor irritant for them. You lose one here, then there, but by bark beetles or root grafts, it (Dutch elm disease) should spread like wildfire through dry grass. And it doesn't."

"There's some sort of ecosystem-level resistance," speculated Lee Frelich, a forest ecologist at the University of Minnesota who learned of the tract only seven or eight years ago.

Owners William and Ute Reid want to make sure that this virgin Elm forest is preserved.