Ya know, I'd never heard of this until I ran across it on YouTube last night.
It turns out that Of Moose & Men: The Rocky & Bullwinkle Story had aired on PBS, of all places, in the winter of 1991. I thought this might've been included with a DVD release of Rocky & His Friends, aka The Bullwinkle Show, and maybe it was, I don't know. Anyway, the only cast members from the cartoon contributing to the special were Bill Scott, June Foray, and narrator William Conrad, who handles those chores here, and it's clear that Conrad's career was winding down. Toward the end of the series' initial run, before it went into eternal repeats, Conrad's narrative had more of the dramatic tone he used in narrating The Fugitive.
Conrad & Scott, of course, have long since left us, but June Foray is still active, amazingly.