Walls and Ceilings - Crack in corner of drywall

I was going to pull up old carpet in a bedroom, and moved the furniture out of the room to discover a thick crack (you can stick your finger through it) in the drywall right at the corner, starting at the base of the floor going about 1/4th up the wall -- there was no visible crack when I moved in 2 years ago. When I pulled back the carpet, along this wall the moulding is about 1/4th inch away from the ends of the hardwood floor boards, leaving a gap that seems to go down into the crawlspace of my 1959 house. When you look closely at the wall you can see an outward bow. I live in Colorado and have been told that soil movement/settling is a big problem here. It seems the wall is moving away from the house? My question, is this fixable? What kind of a professional should I call to examine this? Thank you!