Mapping Data Classifications
This map series visualizes the distribution of public campgrounds across U.S. counties using four different data classification methods: Equal Interval, Quantile, Natural Breaks (Jenks), and Standard Deviation. The data comes from the Recreation Structures feature layer maintained by the U.S. Geological Survey’s National Map. The layer includes geolocated features classified as “campgrounds.” To prepare the dataset for visualization, a spatial join was performed to count the number of campground points within each county polygon. The resulting attribute was the total number of public campgrounds per county.
The study area encompasses the entire U.S to assess where campground density is highest. As we will see, mapping campgrounds showcases how some counties have a large number of campgrounds and while some contain very few or none.
Natural Breaks (Jenks) finds data-driven thresholds that highlight clusters and gaps in campground density, offering a more intuitive representation of the underlying spatial distribution.
Equal Interval divides the range of campground counts into evenly spaced intervals, which tends to group most low-campground counties into the same class and limits contrast.
Quantile ensures each class contains an equal number of counties, which visually balances the map but groups counties with drastically different campground counts together, potentially misleading viewers.
Standard Deviation emphasizes statistical outliers, drawing attention to counties with unusually high or low numbers of campgrounds in relation to the mean.