Overview of the data sources and records available from the citizen monitoring networks included in this study.

Numbers represent totals through 2012.
1Number of lakes determined from 2007 National Hydrography Dataset (NHD) with surface area equal to or greater than 4 ha.
2Includes all citizen Secchi observations available from designated monitoring network.
3http://www.epa.state.il.us/water/vlmp.
4http://www.indiana.edu/~clp.
5http://www.Secchidipin.org.
6http://www.micorps.net/.
7http://www.lmvp.org.
8http://www.pca.state.mn.us/index.php/water/water-types-and-programs/surface-water/lakes/citizen-lake-monitoring-program/index.html.
9http://www.olms.org/citizen-lake-awareness-and-monitoring.
10http://dnr.wi.gov/lakes/CLMN.