| | Acc. No. | Year | Location | County | Observers |
| #26123 | 1950 |
Pearall's Trout Farm, 8 miles s. of Monte Vista
| Rio Grande | Ron Ryder |
| #33819 | 1965 |
Colorado Springs
| El Paso | R. Stabler |
| 34-74-92 | 1971 |
Hack Ranch
| Jefferson | Carol Hack |
| 34-73-52 | 1973 |
Horse Creek Reservoir
| Weld | Harold Holt |
| 34-76-19 | 1975 |
Pastorious Res.
| La Plata | A. Nelson |
| 34-77-18 | 1977 |
Arkansas River, 3 miles NE of La Junta
| Otero | B. Tully |
| 34-81-18 #37401 | 1981 |
Arkon
| Logan | Laurens Halsey |
| 34-82-13 | 1982 |
Alamosa NWR
| Alamosa | J. Kauffeld |
| 34-86-25 | 1985 |
Hudson
| Weld | Jerry Cairo |
| 34-86-11 #39534 | 1986 |
Fort Collins
| Larimer | G. Hughes |
| 34-87-53 | 1987 |
Rollinsville
| Gilpin | R. Cohen |
| 2010-53 | 1987 |
Boulder
| Boulder | Bill Kaempfer |
| 34-90-35 | 1990 |
Chatfield SRA
| Douglas | P. Hayes |
| 34-94-47 | 1994 |
Lake Hasty Campground
| Bent | Mark Janos |
| 34-95-64 | 1995 |
Jumbo Reservoir
| Logan | Jack Reddall |
| 1999-97 | 1999 |
Chatfield State Park
| Douglas | Joey Kellner |
| 2000-87 | 2000 |
Higbee Cemetery
| Otero | Larry Semo |
| 2001-30 | 2001 |
Higbee Cemetery
| Otero | Dave Elwonger, Rachel Hopper, Karleen Schofield, Tom Shane |
| 2001-148 | 2001 |
Belmar Park
| Jefferson | Karleen Schofield, Larry Semo |
| 2001-25 | 2001 |
Chatfield Reservoir
| Douglas | Ric Olson |
| 2001-149 | 2001 |
Cottonwood Canyon
| Baca | Dick Filby |
| 2001-29 | 2001 |
15 miles SSW of Springfield
| Baca | Tony Leukering, Marshall Iliff |
| 2002-190 | 2001 |
Pueblo
| Pueblo | Mark Yaeger |
| 2002-160 | 2002 |
Lamar Community College
| Prowers | Brian Gibbons |
| 2002-58 | 2002 |
just south of Rose Pond, Chico Basin Ranch
| Pueblo | Tony Leukering, Bill Schmoker |
| 2002-155 | 2002 |
near the Higbee Cemetery
| Otero | Roger Linfield |
| 2003-38 | 2003 |
Carrizo Picnic Area, Comanche NG
| Baca | Thom Rahn |
| 2004-15 | 2004 |
Pueblo Reservoir
| Pueblo | David Quady |
| 2005-27 | 2005 |
Two Buttes Res.
| Baca | Brandon K. Percival |
| 2006-25 | 2006 |
Chico Basin Ranch
| El Paso | Bill Maynard, Brandon Percival, Andrew Spencer, Cole Wild |
| 2006-34 | 2006 |
Campo
| Baca | Brian Gibbons |
| 2006-38 | 2006 |
Chico Basin Ranch
| El Paso | Brandon Percival |
| 2006-42 | 2006 |
Campo
| Baca | Brandon Percival |
| 2006-43 | 2006 |
Chatfield SP
| Douglas | Joey Kellner |
| 2008-26 | 2008 |
Highlin State Park
| Mesa | Jason Beason |
| 2008-28 | 2008 |
Canon City Riverwalk
| Fremont | Brandon Percival |
| 2008-34 | 2008 |
Grenada
| Prowers | Brandon Percival |
| 2009-12 | 2009 |
Barr Lake S.P.
| Adams | Bill Schmoker, Cole Wild, Doug Faulkner, Larry Semo |
| 2009-18 | 2009 |
Crow Valley Campground
| Weld | Rachel Hopper |
| 2009-20 | 2009 |
Sawhill Ponds
| Boulder | Nathan Pieplow, Walter Szeliga, Bill Kaempfer, Larry Semo |
| 2009-34 | 2009 |
Florence
| Fremont | Brandon Percival |
| 2010-105 | 2010 |
Karval
| Lincoln | Lisa Edwards |
| 2011-39 | 2011 |
Nucla
| Montrose | Coen Dexter |
| 2011-85 | 2011 |
Thompson Ranch
| Lincoln | Doug Faulkner, Tony Leukering |
| 2013-17 | 2011 |
City park in Campo
| Baca | Randy Siebert |
| 2014-099 | 2012 |
Brett Gray Ranch
| Lincoln | Walbek, Glenn |
| 2014-082 | 2014 |
Not Specified
| Rio Grande | John Rawinski |
| 2015-031 | 2015 |
Pueblo Reservoir area
| Pueblo | Brandon K. Percival |
| 2017-063 | 2017 |
Near Snyder's Pond
| San Miguel | Coen Dexter |
| 2018-021 | 2018 |
Walden Ponds/Sawhill Ponds Complex
| Boulder | Peter Burke |