Omaha is just one city, and Nebraska is a state that may be hard-pressed to keep up with the full demand of Omaha Steaks on its own. The Omaha Steaks website notes that all cattle are directly sourced from the Midwest (read nearby, but maybe not Nebraska). The company advertises that these cattle involved are grass-fed and grain-finished. Highly trained butchers ensure top-quality cuts with marbling and a 21-day aging process. 

Quora users are a bit more skeptical, however, as many people have searched to find the direct sourcing info for this mega-brand. "They don't raise the cattle, they purchase, cut and package the meat for sale. One thing that I found unusual was that other than being USDA inspected, they don't tell you the grade of their beef," (via Quora). The user goes on to add, "I'm sure their products are fine..." alluding to the fact that even if the cows aren't Nebraskan, other than being frozen, there isn't anything about the quality that's blatantly objectionable.