| | Acc. No. | Year | Location | County | Observers |
| 1885-002 | 1885 |
Denver
| Denver | H. Smith |
| 1945-002 | 1945 |
Bennett
| Adams | Alfred Bailey |
| 19-74-78 | 1974 |
Lower Poudre Canyon
| Larimer | Paul Gertler |
| 19-90-19 | 1990 |
Boulder
| Boulder | John Prather, Peter Gent |
| 2013-102 | 1997 |
Valco Ponds
| Pueblo | Brandon K Percival |
| 2000-039 | 2000 |
Rocky Ford State Wildlife Area
| Otero | Stan Oswald, Larry Semo |
| 2001-006 | 2001 |
Lake Henry
| Crowley | Brandon Percival |
| 2005-001 | 2005 |
Sand Creek Greenway
| Adams | Randy Lentz, Joey Kellner, Glenn Walbek, Peter Frechtel |
| 2010-146 | 2010 |
Brighton
| Adams | Robert Espeland |
| 2011-172 | 2011 |
Burlington
| Kit Carson | John Drummond |
| 2014-031 | 2013 |
Fountain Creek Regional Park
| El Paso | Ken Pals |
| 2013-282 | 2013 |
Colorado Springs
| El Paso | Doug Gould |
| 2014-021 | 2014 |
Fountain Creek Regional Park
| El Paso | Cheryl Teuton, Bill Maynard, Brandon Percival |
| 2015-139 | 2015 |
Bobcat Ridge Natural Area
| Larimer | Tom Behnfield, Rudi Nuissl |
| 2015-125 | 2015 |
Colorado State University campus
| Larimer | John Shenot, Andrew Bankert |
| 2016-001 | 2016 |
Bobcat Ridge Natural Area
| Larimer | Holden Maxfield, Gregg Goodrich, Chris Wood, Mark Amershek |