The last time we (CSCC then) ran an event there was in the summer of 1991. My stock Miata was bottoming out because of the asphalt breaking up by the run. We had to move the course a number of times during the day due to the WWII era pavement breaking up. At that time we figured it was not a worthwhile venue due to the asphalt. There was also a bunch of tall grasses growing through the asphalt .... trying to remember, I think we may have had some of it mown before we went there for that one event.
Normal life of asphalt (as per engineering stds) is considered to be about 20 years. WWII is a long time ago.
Current user is an AMA school from what I understand from a few years ago.
So, unless the site is re-paved, it is a no-go, unfortunately.
As a sidenote, DeWinton is one of the former Allied training bases from WWII just like Fort Macleod (if you look at FM, you'll see almost the identical layout for the runways - the triangle). There are quite a few of them throughout Southern Alberta ... Clareholm, Vulcan, and even to the NE of Fort Macleod there is another one.
R