Very very sad to read of this accident.
This report has the accident occurring at 12:00.
https://aviation-safety.net/wikibase/wiki.php?id=212026
From Weather Underground, wind on June 9 at 11:56 at Driggs was 21 mph gusting to 25 mph, sky clear. Wind in the nearby mountains at 10,800 ft might have been greater and might have been more gusty:
https://www.wunderground.com/history...ic=&reqdb.wmo=