I'm doing some hydrology research and looking for a geospatial mapping package to visualize some of my results. I currently have data at 41 different locations in Wisconsin, locations for which I have a set of pairs of latitude and longitude coordinates. Each location has various factors associated with it (depth of 100-year rainfall, fitted distribution parameters, etc).
I'm looking for a package where I can take a blank map of the state of Wisconsin, plot points at my 41 different locations, and have the points' sizes and colors vary according the value of the factor at that location. Ideally, I'm looking for as minimalist of a map as possible.
I've already tried the ggmap package, but the syntax is a jungle. Even when I can get my code to run the maps aren't displaying in the way I want them to and I can't tell what I'm doing wrong. Any suggestions?