Mountain Yellow-legged Frog (Rana muscosa)
- Photos of this species and its habitat. Includes identifying traits and facts on natural history, range, reproduction, and conservation status.
- http://www.californiaherps.com/frogs/pages/r.muscosa.html

Family Ranidae
- Classification, information, pictures, and sounds. From the Animal Diversity Web.
- http://animaldiversity.ummz.umich.edu/site/accounts/classification/Ranidae.html

Water Frog Information Pool
- Information about several species and hybrids in the genus Rana.
- http://evolution.genetics.washington.edu/waterfrogs.html

California Red-Legged Frog
- Information about Rana aurora draytonii, a threatened frog of the western US.
- http://www.hyperlogik.com/CRLF/