Hi Dave, welcome to the great monkey-or-not poop toss.
Yeah, the moose-cow is a tabloid myth. Ranchers in Minnesota occasionally blame deformed calves on the horny bull moose; the two examples that got some press turn out to be endocrine problems, probably caused by a combination of recessive genes.
http://jhered.oxfordjournals.org/cgi/pdf_extract/30/10/457
Beefalo, on the other hand, are delicious, and have moved on from problematic attempts to a succesful breed of cattle. They have totally sabotaged "pure" bison conservation, though, as they fill the niche better than their endangered kinfolk.
Beefalo - Wikipedia
Remember that old Star Trek where they talk about the buffalo being extinct? It's the one with the sexy salt-sucker in it who puts the make on everyone in the ship, McCoy's ex-girlfriend, tells Uhura he is a "Swahili" etc.
Anyway I won a huge bet on that one time, I had a buddy who really believed they were gone!
He had faith in Mr. Spock ...