William, the good news is you get to enjoy the leaves for a while. The bad news is that these trees need to be propagated by planting the nuts or by grafting, which appears to be difficult for this tree. Here's some sites you should find informative.
http://www.atl.cfs.nrcan.gc.ca/index...tternut-e.html
http://www.fnr.purdue.edu/inwood/pas...tButternut.htm
http://www.na.fs.fed.us/spfo/pubs/ho...but/ht_but.htm
http://www.cobjon.com/butternut.html

And from this site:
http://ecsong.ca/vol15no1.html#P
"Butternut Salvage

As most of you already know, the butternut population across North America is being devastated by a fatal canker disease. Already most southern butternuts have gone, and the infection are wide spread even here in the north. A program is underway to find and propagate butternuts shown to be resistant. There is reason to be optimistic as such trees are known to exist.

However, most trees are doomed. Guy Lefebvre and others have suggested that dying trees should be cut, in part to possibly slow the spread, but at the same time to at least gain the wood. Though the logging industry might be interested in such a harvest in ideal conditions, most butternuts are too isolated to offer economical advantage. If you are the owner of a doomed tree, you could consider harvesting it yourself. This would remove the illness from the site, and provide you with valuable butternut wood that could be crafted into future heirloom furniture for your progeny. Members are invited to contact ECSONG's new chair, Len Collett, who is interested in such work and may be able to advise or assist you in your endeavour."

Newt