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At Lily Park, nonnative fishes comprised 44% of the fish community in 2007, the only year that Lily Park was sampled. Smallmouth bass were the dominant nonnative species, comprising 25% of the fish community and flannelmouth sucker were the most dominant native species, comprising 47% of the fish community. In 2007, abundance of all fish as measured by CPUE, was four times higher at Lily Park compared to abundance at Little Yampa Canyon indicating higher production at Lily Park. Comparisons of our 1-mile samples from 2007, our most recent data, with similar electrofishing samples collected 23 years earlier (Wick et al. 1985) revealed substantial increases in diversity and abundance of nonnative fishes and declines in native fishes. At Little Yampa Canyon, relative abundance of native species declined dramatically from 68 to 3% of the fish community from the earlier sampling to present and at Lily Park, native fishes declined from 91 to 57% during the same period (Table 16). Smallmouth bass had the most dramatic increase in abundance between the two time periods increasing from 0.3 to 51 % of the fish community at Little Yampa Canyon and from zero to 25% of the fish community at Lily Park. Increases were also observed for nonnative white sucker and northern pike and minor declines were observed for nonnative common carp and channel catfish. Native roundtail chub Gi/a robusta, flannelmouth sucker, and bluehead sucker Catostomus discobo/us which together comprised 66% of the Little Yampa Canyon fish community in 1983-1984 declined to only 3% of all fish collected in 2007. At Lily Park, each of those three natives also declined in abundance between the two time periods, but flannel mouth sucker still comprised 47% of the fish community at Lily Park. Flannelmouth sucker and to some extent bluehead sucker were apparently persisting at Lily Park in the presence of large numbers of small mouth bass. Recent sampling in 2007 also collected four piscivorous nonnative species not observed by Wick et al. (1985) including: bluegill, creek chub Semoti/us atromacu/atus, brown trout Sa/mo trutta, and brook trout Sa/velinus fontina/is. Overall abundance of fish, as measured by CPUE, declined from 1983 and 1984 to 2007. Assuming catch efficiency was similar between periods, at Little Yampa Canyon 4.5 times more fish were collected in 1983-1984 (148 fish/hour) than in 2007 (33 20