| | Acc. No. | Year | Location | County | Observers |
| 1950-001 | 1950 |
8 miles S of Monte Vista
| Rio Grande | Ron Ryder |
| 1965-001 | 1965 |
Colorado Springs
| El Paso | Robert Stabler |
| 34-74-92 | 1971 |
4 mls from Jefferson
| Park | Carol Hack |
| 34-73-52 | 1973 |
Horse Creek Reservoir
| Weld | Harold Holt |
| 34-76-19 | 1975 |
Pastorius State Wildlife Area
| La Plata | Alan Nelson |
| 34-77-18 | 1977 |
La Junta
| Otero | Babette Tully |
| 34-81-18 | 1981 |
Akron
| Logan | Laurens Halsey |
| 34-82-13 | 1982 |
Alamosa National Wildlife Refuge
| Alamosa | Jon Kauffeld |
| 34-86-25 | 1985 |
Hudson
| Weld | Jerry Cairo |
| 34-86-11 | 1986 |
Fort Collins
| Larimer | Greg Hughes |
| 34-87-53 | 1987 |
Rollinsville
| Gilpin | Robert Cohen |
| 2010-053 | 1987 |
Boulder Creek & 75th Street
| Boulder | Bill Kaempfer |
| 34-90-35 | 1990 |
Chatfield State Park (Douglas Portion)
| Douglas | Philip Hayes |
| 34-94-47 | 1994 |
John Martin Reservoir State Park
| Bent | Mark Janos |
| 34-95-64 | 1995 |
Jumbo Reservoir State Wildlife Area
| Logan | Jack Reddall |
| 1999-097 | 1999 |
Chatfield State Park (Douglas Portion)
| Douglas | Joey Kellner |
| 2000-087 | 2000 |
Higbee Cemetery
| Otero | Laurie Zuckerman, David Quesenberry, David Elwonger, Joe Mammoser, Larry Semo |
| 2001-030 | 2001 |
Higbee Cemetery
| Otero | David Elwonger, Tony Leukering, Rachel Kolokoff, Karleen Schofield, Tom Shane |
| 2001-148 | 2001 |
Belmar Historic Park
| Jefferson | Karleen Schofield, Larry Semo |
| 2001-025 | 2001 |
Chatfield State Park (Douglas Portion)
| Douglas | Ric Olson |
| 2001-149 | 2001 |
Cottonwood Canyon
| Baca | Dick Filby |
| 2001-029 | 2001 |
Baca CRs 23 & Q
| Baca | Tony Leukering, Marshall Iliff |
| 2002-190 | 2001 |
Pueblo
| Pueblo | Mark Yaeger |
| 2002-160 | 2002 |
Lamar
| Prowers | Brian Gibbons |
| 2002-058 | 2002 |
Chico Basin Ranch
| Pueblo | Bill Schmoker, Tony Leukering |
| 2002-155 | 2002 |
Higbee Cemetery
| Otero | Roger Linfield |
| 2003-165 | 2003 |
Alamosa
| Alamosa | Josiah Malueg |
| 2003-038 | 2003 |
Carrizo Canyon Picnic Area
| Baca | Thom Rahn |
| 2004-015 | 2004 |
Pueblo Reservoir area
| Pueblo | Donald Lewis, David Quady |
| 2005-027 | 2005 |
Two Buttes State Wildlife Area
| Baca | Brandon K. Percival |
| 2006-025 | 2006 |
Chico Basin Ranch
| El Paso | Bill Maynard, Brandon Percival, Andrew Spencer, Cole Wild |
| 2006-034 | 2006 |
Campo
| Baca | Brian Gibbons |
| 2006-038 | 2006 |
Chico Basin Ranch
| El Paso | Brandon Percival |
| 2006-042 | 2006 |
Campo
| Baca | Brandon Percival |
| 2006-043 | 2006 |
Chatfield State Park (Douglas Portion)
| Douglas | Joey Kellner |
| 2008-026 | 2008 |
Highline Lake State Park
| Mesa | Jason Beason |
| 2008-028 | 2008 |
Canon City Riverwalk
| Fremont | Brandon Percival |
| 2008-034 | 2008 |
CRs 28 & D
| Prowers | Brandon Percival |
| 2009-012 | 2009 |
Barr Lake State Park
| Adams | Bill Schmoker, Cole Wild, Doug Faulkner, Larry Semo |
| 2009-018 | 2009 |
Crow Valley Campground
| Weld | Rachel Hopper |
| 2009-020 | 2009 |
Walden Ponds/Sawhill Ponds Complex
| Boulder | Nathan Pieplow, Walter Szeliga, Bill Kaempfer, Larry Semo |
| 2009-034 | 2009 |
Florence
| Fremont | Brandon Percival |
| 2010-105 | 2010 |
Karval State Wildlife Area
| Lincoln | Lisa Edwards |
| 2011-039 | 2011 |
Nucla
| Montrose | Coen Dexter |
| 2011-085 | 2011 |
Thompson Ranch
| Lincoln | Doug Faulkner, Tony Leukering |
| 2013-017 | 2011 |
Campo
| Baca | Randy Siebert |
| 2014-099 | 2012 |
Brett Gray Ranch
| Lincoln | Glenn Walbek |
| 2014-082 | 2014 |
Del Norte West to South Fork
| 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 |
| 2025-001 | 2025 |
Lyons
| Boulder | Sheila Webber |