Flight Crew Private
Flight Crew Total 385
Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Environment - Non Weather Related
Aircraft Y was flying south in front of us quite a distance (approx 10-15 miles).  ADS-B in data from my Garmin GDL50 and Foreflight stated he was -200ft below us.  It appeared he was at our elevation or maybe slightly higher; but was hard to tell for sure due to the distance and size of the aircraft.I flew along north of PUB as Aircraft Y made a right hand turn to line up with a runway at COS.  I was thinking about wake turbulence from their aircraft; but with the data I had; we were above them and should be no factor.  A few minutes later we hit severe wake turbulence causing the airplane to violently roll to the left while losing altitude.  I reacted quickly and kept the airplane level and under control.  There were no injuries or damage; but there certainly could have been as my passenger hit their head on the interior.As Aircraft Y approached COS; their ADS-B still said they were level with us but COS would have been a couple thousand feet below.  So something is amiss with either [their] ADSB or the radar rebroadcast.
Reporter stated the other aircraft was a large four-engine transport.
Cessna 182 pilot reported encountering wake turbulence from another aircraft in the vicinity of COS airport.