The PDF was a map of infrastructure that was likely produced with ArcGIS. By the time I got it, it was just a vector image. The infrastructure in question was

The PDF was a map of infrastructure that was likely produced with ArcGIS. By the time I got it, it was just a vector image. The infrastructure in question was pipelines, represented in the PDF by lines, so georeferencing them was enough to get spatial data adequate for the application.