This map depicts the availability of LIDAR data for counties within the Chesapeake Bay watershed, and is symbolized by both the availability and quality of LIDAR data. Counties are labeled with the year(s) that currently available data was acquired.

LIDAR quality is represented by one of three levels, with Quality Level 1 (QL1) being the highest quality. LIDAR quality levels are defined in the following document: https://pubs.usgs.gov/tm/11b4/pdf/tm11-B4.pdf

This dataset is updated periodically by the USGS MD-DE-DC Water Science Center, and is shared with the Chesapeake Bay Program. The date of the latest version is incorporated into the map title.

A PDF version is available here.