Update:
Well, it was too good to last. I've been buying this stuff for the past three years when we visited Fort Davis. When I first started buying it in 2003, the herds were being raised in the counties of Brewster, Pecos, Jeff Davis, and Reeves. The old labels on the packaging were complete with the "Go Texan" symbol given out by the Texas Ag department for Texas products.

The latest batch that arrived: no "Go Texan" label to be found. So I talked to them. It seems that in a move to appease growing demand, most notably from Whole Foods, they had to move their herds north earlier this year. The Fed Ex box newly arrived on my doorstep now indicates that it shipped from Iowa. Yep, it's no longer Texas beef.
I have not yet tried the new beef, so I don't yet know if there will be any difference in taste or quality. Sadly, I am guessing that this will be my last order.