| Acc. No. | Year | Location | County | Observers |
| 1902-003 | 1902 |
Windsor Reservoir
| Weld | Elmer Sutter, Alexander Wetmore |
| 22-73-115 | 1973 |
Cherry Creek State Park
| Arapahoe | Harold Holt |
| 22-92-18 | 1992 |
Chatfield State Park
| Douglas | Mark Nikas, Dick Schottler, Joey Kellner, Steve Stachowiak, Mark Janos |
| 22-93-41 | 1993 |
Blue Lake (Adobe Creek Reservoir)
| Bent & Kiowa | Pearle Sandstrom-Smith |
| 22-93-102 | 1993 |
Union Reservoir
| Weld | Dave Leatherman, Peter Gent |
| 22-95-35 | 1995 |
Barr Lake State Park
| Adams & Weld | Tony Leukering, Bob Righter, Ric Olson |
| 2001-209 | 2000 |
Jackson Reservoir
| Morgan | Dick Schottler, Rachel Kolokoff, Tony Leukering |
| 2001-143 | 2001 |
Standley Lake
| Jefferson | Larry Semo, Rachel Hopper, Peter Gent, Karleen Schofield |
| 2003-151 | 2003 |
Barr Lake State Park
| Adams | Tony Leukering |
| 2004-129 | 2004 |
Fossil Creek Reservoir
| Larimer | Rachel Hopper |
| 2005-089 | 2005 |
Prewitt Reservoir State Wildlife Area
| Washington | Roger Linfield, Tony Leukering, Larry Griffin |
| 2005-092 | 2005 |
Colorado City and Rye
| Pueblo | David Silverman |
| 2005-097 | 2005 |
Prewitt Reservoir State Wildlife Area
| Washington & Logan | Andrew Spencer |
| 2007-063 | 2007 |
Claymore Lake
| Larimer | Ken Ecton |
| 2007-088 | 2007 |
Boulder Reservoir
| Boulder | Bill Schmoker, Thomas Heinrich |
| 2008-103 | 2008 |
Cherry Creek State Park
| Arapahoe | Andrew Spencer, Nick Komar, Glenn Walbek, Loch Kilpatrick |
| 2009-118 | 2008 |
Jackson Reservoir
| Morgan | Bill Kaempfer |
| 2008-120 | 2008 |
Chatfield State Park
| Douglas & Jefferson | Andrew Spencer |
| 2011-007 | 2009 |
Grand Junction
| Mesa | Coen Dexter |
| 2010-094 | 2010 |
Cherry Creek State Park
| Arapahoe | Nick Komar, Glenn Walbek |
| 2011-115 | 2011 |
Cherry Creek State Park
| Arapahoe | John Drummond, Bill Maynard |
| 2011-122 | 2011 |
Antero Reservoir
| Park | Bill Maynard |
| 2011-139 | 2011 |
Pueblo Reservoir area
| Pueblo | Brandon Percival, Bill Maynard |
| 2011-162 | 2011 |
Pueblo Reservoir area
| Pueblo | Bill Maynard |
| 2014-131 | 2014 |
Pueblo Reservoir area
| Pueblo | Brandon Percival, Bill Maynard |
| 2014-155 | 2014 |
Boyd Lake State Park
| Larimer | Nicholas Komar |
| 2014-142 | 2014 |
Boulder Reservoir
| Boulder | David Dowell, Steven Mlodinow |
| 2017-053 | 2017 |
Antero Reservoir
| Park | Steven Mlodinow |
| 2017-054 | 2017 |
Antero Reservoir
| Park | Kathy Mihm Dunning |
| 2018-066 | 2018 |
Alamosa Canyon and Cat Creek Canyon
| Conejos | John Rawinski |
| 2018-024 | 2018 |
Pueblo Reservoir area
| Pueblo | Brandon K. Percival |
| 2020-050 | 2020 |
Jackson Reservoir
| Morgan | Ryan Bushong |
| 2020-094 | 2020 |
Grand Junction
| Mesa | Amy Hudechek |
| 2021-040 | 2021 |
Antero Reservoir
| Park | Luke Pheneger |
| 2023-027 | 2023 |
Lake Meredith
| Crowley | Brandon K. Percival |
| 2023-050 | 2023 |
Boyd Lake State Park
| Larimer | Nicholas Komar |