Adding styles for global roads
Simplifying bounds and zoom levels

Reduces the file size if we ever put this up on the web.
Adding references for the global road data
Adding icons for various dams

I want to use some sort of symbol to represent dams beyond just a dot.
This are some quick mockups for testing the visual style.
Re-enabling the background ocean color
Changing zoom levels

We don't need to zoom in very much. This is mostly a global map.
Smaller railroad lines
Adding a global dams data set with styles

The GRanD dataset includes global dams of signifigant size.