Colorado lake survey results

A gill net is a wall of mesh hung in the water. Fish swim into it and are held by the gills. CPW sets a standard number of nets overnight, pulls them in the morning, and identifies, counts, weighs and measures the catch. Where a report states how many nets were set, that is shown beside the lake.

A zero is weak evidence. Mesh selects for a size range, so fish much smaller or much larger than the mesh pass through or are never held. CPW states in its Dillon Reservoir report that Kokanee Salmon in particular “are known to be difficult to capture and monitor with gillnet surveys”. A species missing from a table was not caught in those nets; that is not the same as absent from the lake.

Counts are not comparable across lakes. One survey may be eight overnight nets on a 2,000-acre reservoir and another a single net in an alpine basin. The sport-fish share is a ratio within a single survey, so it compares; the raw counts do not.

Ages differ by a decade. The oldest survey here is 2013 and the newest 2025. A survey year sits beside every number on this page for that reason.

Where CPW's own table is inconsistent, the value is withheld rather than shown, with the reason printed in place. One wilderness row prints a mean length that falls outside its own stated range; another handful of single-fish rows print no range at all, leaving no way to tell a length column from a weight column. In both cases the count is unaffected and is shown.

Extracted from the CPW fishery survey summaries indexed on this site, reviewed 2026-10-18. Every figure on this page links to the survey it came from.