Environmental DNA has been highly successful at detecting fish species, particularly at low abundances when they are not detectable using traditional methods (such snorkeling, seining, or electrofishing). We are currently using eDNA to map the presence of native fish species including steelhead trout (Oncorhynchus mykiss), Santa Ana sucker (Catostomus santaanae), and Pacific lamprey (Entosphenus tridentatus) as well as non-natives including largemouth bass (Micropterus salmoides) and common carp (Cyprinus carpio). We are also using eDNA sampling to assess the effects of fire on local native and non-native fish distributions.