DLG - Lake Tahoe

http://tahoe.usgs.gov/DLG.html

Digital line graphs (DLGs) are a collection of cartographic features depicted through vectors by the USGS.  Storing this data in a digital format allows for easy modifications to take place and decreases the amount of paper maps that need to be used.

The above DLG map of lake Tahoe has many different features.  The red lines represent roads, blue represents both rivers and lakes, and the greens represent vegetation.  Having this digital input of data is extremely important for GIS applications as well.  the vector form of this data allows for in depth data analysis for a variety of different purposes.