A survey of lakes and streams was conducted in 2004 for fish and amphibians. This survey detected nine species of fish of which five are native to parts of California. Native species include rainbow trout, tui chub, speckled dace, Lahontan redside and Tahoe sucker. Brook trout, Brown trout, golden shiner, and fathead minnow are all species that are non-native to the park that were detected during this survey. Fish stocking occurred prior to the park being established in 1916. Most of the lakes in the park were stocked with rainbow, brown, and brook trout. It is suspected that the golden shiner and fathead minnow were introduced as bait that was used by fishermen and escaped. Due to National Park Service policy, all stocking of fish was halted in the park and currently most of the lakes where these fish were planted are currently fishless due to lack of suitable spawning grounds.