Butterflies of Clark County - Presents photos and species accounts of butterflies found within the county. www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/chklist/states/counties/oh_23.htm
Clark County Ground-Water Resources - Factsheet providing information on ground-water resources in the county. ohioline.osu.edu/aex-fact/0490_12.html
Clark County Water Resources - Factsheet providing information on water resources and drinking-water quality in the county. ohioline.osu.edu/aex-fact/0480_12.html
