- The United States (U.S.) has seen dramatic growth in installed wind energy generation capacity in recent years, and that growth is expected to remain strong in the near term. The siting of wind energy facilities poses unique challenges that may be exacerbated by increased buildout. As the number of wind farm installations throughout the U.S. continues to grow, developers will continue to draw from a finite number of suitable sites. Are there observable trends in wind siting practices that would demonstrate a shift toward less suitable sites when availability is diminished by saturation? Additionally, are there trends that would instead suggest evolving constraints are altering what is considered to be a suitable site? This paper explores the drivers and constraints of wind energy development and siting and examines spatial trends that could be used to indicate that wind farms are being constructed in sites with suboptimal suitability. Additionally, this paper discusses existing evidence of evolving constraints, and therefore, a changing definition of a “suitable site.” Spatial analyses of constraints including land use, population density, distance to transmission lines, and proximity to sensitive wildlife areas were performed in conjunction with a review of existing datasets. The results of these analyses do not demonstrate an overall shift toward less suitable sites, which suggests no current scarcity of such sites. Additionally, other studies have suggested that evolving turbine technology may be affecting the extent to which wind resource availability constrains siting, potentially broadening the definition of a suitable site. The paper concludes with a discussion of the implications of the spatial analyses, and opportunities for further research.