| | Acc. No. | Year | Location | County | Observers |
| 1895-001 | 1895 |
Loveland
| Larimer | E. Preble |
| 21-72-18 | 1972 |
Pueblo Reservoir area
| Pueblo | Dave Griffiths, Van Truan |
| 21-75-64 | 1975 |
Monte Vista National Wildlife Refuge
| Rio Grande | Charles R. Bryant, William F. Johnson |
| 21-75-149 | 1975 |
Barr Lake State Park
| Adams | Robert Andrews |
| 21-75-133 | 1975 |
Barr Lake State Park
| Adams | Jack Reddall, Robert Andrews, Harold Holt |
| 21-76-91 | 1976 |
Barr Lake State Park
| Adams | Jack Reddall, Robert Andrews |
| 21-80-22 | 1979 |
Meeker
| Rio Blanco | M. Getman |
| 21-82-38 | 1980 |
Chatfield State Park
| Douglas & Jefferson | Robert Andrews |
| 21-82-42 | 1981 |
Prewitt Reservoir State Wildlife Area
| Washington | Robert Andrews |
| 21-81-54 | 1981 |
Barr Lake State Park
| Adams | Hugh Kingery |
| 21-83-29 | 1983 |
Red Lion State Wildlife Area
| Logan | Laurens Halsey |
| 21-88-8 | 1987 |
Jackson Reservoir
| Morgan | Jerry Cairo |
| 21-90-20 | 1990 |
Blue Lake (Adobe Creek Reservoir)
| Kiowa & Bent | Duane Nelson, Mark Janos |
| 21-90-21 | 1990 |
Prewitt Reservoir State Wildlife Area
| Washington | Dan Bridges |
| 21-92-43 | 1992 |
6 mi N of Firstview
| Cheyenne | Hugh Kingery |
| 21-92-39 | 1992 |
Lake Holbrook
| Otero | Mark Janos |
| 21-93-96 | 1993 |
Blue Lake (Adobe Creek Reservoir)
| Bent | Karleen Schofield |
| 21-96-17 | 1996 |
Duck Lake
| Larimer | Dave Ely, William & P. Lisowsky, Joe Mammoser |
| 1997-033 | 1997 |
Antero Reservoir
| Park | Tony Leukering |
| 1997-034 | 1997 |
Duck Lake
| Larimer | Steve Dinsmore |
| 2000-040 | 2000 |
Jumbo Reservoir State Wildlife Area
| Logan | Chris Wood |
| 2000-041 | 2000 |
Jackson Reservoir
| Morgan | Doug Faulkner |
| 2001-094 | 2001 |
Jackson Reservoir
| Morgan | Brian Gibbons, Bill Schmoker |
| 2002-197 | 2002 |
Jackson Reservoir
| Morgan | Doug Faulkner, Rachel Hopper |
| 2002-074 | 2002 |
Beebe Draw
| Weld | Ric Olson |
| 2002-086 | 2002 |
Vega State Park and Reservoir
| Mesa | Rich Levad |
| 2003-066 | 2003 |
Barr Lake State Park
| Adams | Tony Leukering |
| 2004-087 | 2003 |
Eleven Mile State Park
| Park | Andrew Spencer, Nathan Pieplow |
| 2003-039 | 2003 |
Lake Henry
| Crowley | Andrew Spencer |
| 2004-049 | 2004 |
Jackson Reservoir
| Morgan | Brian Gibbons, Roy Halpin |
| 2005-086 | 2005 |
Prewitt Reservoir State Wildlife Area
| Washington | Bill Schmoker |
| 2005-104 | 2005 |
Chatfield State Park
| Jefferson & Douglas | Andrew Spencer |
| 2005-108 | 2005 |
Boulder Reservoir
| Boulder | Bill Schmoker |
| 2005-110 | 2005 |
Fruitgrowers Reservoir (Hart's Basin)
| Delta | Andrew Spencer, Nathan Pieplow |
| 2006-143 | 2006 |
Chatfield State Park
| Douglas & Jefferson | Andrew Spencer |
| 2007-040 | 2007 |
Pond 0.5 miles south of CR 122 and CR 45
| Weld | Gregg Goodrich, Andrew Spencer, Bill Maynard, Doug Faulkner |
| 2007-058 | 2007 |
Cherry Creek State Park
| Arapahoe | Glenn Walbek |
| 2007-074 | 2007 |
Twin Lakes (Lake County)
| Lake | Tim Kalbach |
| 2007-092 | 2007 |
Cherry Creek State Park
| Arapahoe | Bill Maynard |
| 2008-109 | 2008 |
De Weese Reservoir
| Custer | Rich Miller |
| 2008-117 | 2008 |
Cottonwood Marsh
| Delta | Andrew Spencer, Nick Komar |
| 2009-085 | 2009 |
Timnath Reservoir
| Larimer | Rachel Hopper |
| 2010-098 | 2010 |
Huerfano Reservoir area
| Pueblo | David Silverman |
| 2010-124 | 2010 |
Redlands Parkway South Pond
| Mesa | Robert Bradley |
| 2010-135 | 2010 |
Baseline Reservoir
| Boulder | Ted Floyd, Cole Wild |
| 2011-106 | 2011 |
Empire Res.
| Morgan | Rolando Garcia |
| 2011-127 | 2011 |
Boulder Reservoir
| Boulder | Norm Lewis |
| 2011-123 | 2011 |
Antero Reservoir
| Park | Bill Maynard |
| 2013-101 | 2012 |
Ridgway Reservoir
| Ouray | Coen Dexter |
| 2014-085 | 2014 |
Wahatoay Lake Reservoir
| Huerfano | Polly Wren Neldner, Brandon Percival |
| 2016-009 | 2016 |
Pueblo Reservoir area
| Pueblo | Brandon K. Percival |