In this dissertation I explore environmental practices and environmental regulations in Alberta, Canada's in situ oil sands industry. The in situ oil sands industry provides an interesting context for studying these two phenomena because it was undergoing a period of high growth and subject to immense public scrutiny, particularly in regards to environmental issues. I begin by asking the question: Who does what institutional work on environmental regulations and practices in Canada's oil sands? I explore this broad research question using analytic induction, a qualitative research method that allows the researcher to explore phenomena from a pre­ determined theoretical lens. In my case, this lens is institutional work. I include many different types of organizations in my sample of 67 semi-structured interviews. As I progress through my analysis I discover that much of the work done on practices and regulations involves boundaries. Boundary work emerges as an important aspect of institutional change, as does the type of actor doing the work and the boundary being worked on. I develop propositions based on the strength of boundaries, the position of actors in the field of in situ oil sands, and the boundary the work is done on.