- Butterflies of North America
A USGS site consisting of constantly updated distribution maps, photos, species accounts, and species checklists for each county in the U. S. and state in northern Mexico.
- Connecticut Butterfly Atlas
The Connecticut Butterfly Atlas was a five-year undertaking begun in 1995 with a primary goal of mapping the distribution of Connecticut butterfly species. The website includes methodology, summary statistics and distribution maps.
- Herschel Raney's Butterflies of Arkansas
- Massachusetts Butterfly Club
The Massachusetts Butterfly Club sponsors state-wide butterfly activities to promote education, conservation, interpretation, and fun!
- North American Butterfly Association
The North American Butterfly Association (NABA) is a national, membership-based not-for-profit organization working to increase public enjoyment and conservation of butterflies. It has members throughout the United States, Canada and Mexico.
- Vermont Butterfly Survey
The Vermont Butterfly Survey (VBS), a project of the Vermont Institute of Natural Science, is a five-year census to document the relative abundance and distribution of butterflies across Vermont.