| | Acc. No. | Year | Location | County | Observers |
| 1-73-142 | 1973 |
Marston Reservoir
| Jefferson | Harold Holt, Jack Reddall, Van A. Truan |
| 1974-001 | 1974 |
Antero Reservoir
| Park | Unknown |
| 1-76-106 | 1976 |
Sloan's Lake
| Denver | Bob Andrews, Jack Reddall, John R. Cooper, Van Remsen |
| 1-78-18 | 1977 |
McLellen Reservoir
| Arapahoe | Robert Andrews, Michael Moulton |
| 1-82-37 | 1980 |
Jumbo Reservoir State Wildlife Area
| Logan | Richard C. Rosche |
| 1-83-02 | 1982 |
Chatfield State Park
| Douglas & Jefferson | Mark Holmgren |
| 1-84-5 | 1983 |
Jumbo Reservoir State Wildlife Area
| Logan | Steve Larson |
| 1-87-106 | 1984 |
Lower Latham Reservoir
| Weld | Jerry Cairo |
| 1-86-59 | 1986 |
Cherry Creek State Park
| Arapahoe | Peter Gent |
| 1-88-11 | 1987 |
Pueblo Reservoir area
| Pueblo | David Silverman |
| 1-90-1 | 1990 |
Pueblo Reservoir area
| Pueblo | Mark Janos |
| 1-91-1 | 1991 |
Vega State Park and Reservoir
| Mesa | Coen Dexter |
| 1-91-2 | 1991 |
Chatfield State Park
| Jefferson & Douglas | Joey Kellner |
| 1-93-6 | 1992 |
Highline Lake State Park
| Mesa | Richard Levad |
| 1-92-8 | 1992 |
Cherry Creek State Park
| Arapahoe | Mark Janos |
| 1-93-4 | 1993 |
Chatfield State Park
| Douglas | J.B. Hayes |
| 1-93-100 | 1993 |
Cherry Creek State Park
| Arapahoe | Jack Reddall |
| 1-94-1 | 1994 |
Lake Henry
| Crowley | Mark Janos |
| 1997-003 | 1994 |
North Sterling State Park
| Logan | Jack Reddall |
| 1998-001 | 1995 |
Chatfield State Park
| Jefferson | Brandon K. Percival |
| 1-96-1 | 1996 |
Lake Holbrook
| Otero | Mark Janos |
| 1997-004 | 1997 |
John Martin Reservoir State Park
| Bent | Steven Dinsmore |
| 1997-109 | 1997 |
Snyder
| Morgan | Dave Leatherman |
| 1999-001 | 1999 |
Wolford Mountain Reservoir
| Grand | Jim Liewer |
| 1999-002 | 1999 |
Jumbo Reservoir State Wildlife Area
| Logan | Paul Sweet |
| 2000-001 | 2000 |
John Martin Reservoir State Park
| Bent | Tony Leukering |
| 2000-002 | 2000 |
Ramah State Wildlife Area
| El Paso | Alan Versaw |
| 2000-003 | 2000 |
Pueblo Reservoir area
| Pueblo | Tony Leukering |
| 2001-092 | 2001 |
Standley Lake
| Jefferson | Larry Semo, Ric Olson, Tony Leukering |
| 2003-125 | 2003 |
Standley Lake
| Jefferson | Roger Linfield, Larry Semo |
| 2004-111 | 2004 |
Standley Lake
| Jefferson | Doug Faulkner |
| 2004-063 | 2004 |
Chatfield State Park
| Jefferson & Douglas | Bill Schmoker, Glenn Walbek |
| 2004-135 | 2004 |
Pueblo Reservoir area
| Pueblo | Brandon K. Percival |
| 2005-116 | 2005 |
Pueblo West
| Pueblo | Brandon K Percival |
| 2010-067 | 2005 |
Jumbo Reservoir State Wildlife Area
| Logan & Sedgwick | Steve Larson |
| 2006-150 | 2006 |
Chatfield State Park
| Douglas | Joey Kellner |
| 2007-023 | 2007 |
Pueblo Reservoir area
| Pueblo | Bill Maynard, Brandon Percival |
| 2007-089 | 2007 |
Union Reservoir
| Weld | Nathan Pieplow |
| 2007-093 | 2007 |
Pueblo Reservoir area
| Pueblo | Brandon Percival |
| 2007-097 | 2007 |
Union Reservoir
| Weld | Nathan Pieplow, Andrew Spencer |
| 2008-004 | 2008 |
Pueblo Reservoir area
| Pueblo | Brandon Percival, Tony Leukering |
| 2008-127 | 2008 |
Sweitzer Lake State Park
| Delta | Jason Beason |
| 2009-041 | 2009 |
Brush Hollow Reservoir and State Wildlife Area
| Fremont | Brandon Percival |
| 2009-102 | 2009 |
Union Reservoir
| Weld & Pueblo | Nathan Pieplow, Brandon Percival, Bill Maynard |
| 2010-144 | 2010 |
Chatfield State Park
| Douglas | Joey Kellner, Cole Wild |
| 2010-149 | 2010 |
Pueblo Reservoir area
| Pueblo | Brandon Percival, Bill Maynard |
| 2010-150 | 2010 |
Cherry Creek State Park
| Arapahoe | Glenn Walbek, Cole Wild |
| 2011-035 | 2011 |
Cherry Creek State Park
| Arapahoe | Cheryl Teuton |
| 2011-154 | 2011 |
Pueblo Reservoir area
| Pueblo | Brandon Percival, Bill Maynard |
| 2011-158 | 2011 |
Baseline Reservoir
| Boulder | Christian Nunes, Bill Kaempfer, Peter Gent |
| 2014-100 | 2012 |
John Martin Reservoir State Park
| Bent | Stulp, Jane |
| 2016-046 | 2016 |
Highline Lake State Park
| Mesa | Mike Henwood |
| 2024-033 | 2024 |
Prewitt Reservoir SWA
| Washington | Luke Pheneger |