The Gascone is a French Beef Cattle breed and as far as I know there only was one Gascone bull that was imported in to North America that I know of his semen is being sold by: Universal Semen Sales that is in MT.
Universal Semen Sales does have a web page.
If I do remeber right the Gascone breed was imported in to North American in the early 1970's. I do think one or two fullblood Gascone cows did go some where in Texas!
Gascone cattle are related to Piedmontese and to the Blondes.
From the data that I have read from France there a very hardy breed.
Gascone breeders in the UK have done a few things with the Gascone breed and the do have a little proformance data but so far I have not read any of it. It was published on a few web pages.