| | Acc. No. | Year | Location | County | Observers |
| 8-83-23 | 1980 |
Pawnee Buttes and Pawnee N. Grassland (E. section)
| Weld | Bill Prather |
| 8-92-73 | 1992 |
Monte Vista National Wildlife Refuge
| Rio Grande | John Rawinski |
| 1999-019 | 1993 |
Union Reservoir
| Weld | Virginia Dionigi |
| 8-95-17 | 1995 |
Severance area
| Weld | John Barber |
| 8-96-13 | 1996 |
Barr Lake State Park
| Adams | Jack Reddall |
| 1999-020 | 1999 |
Utah Park
| Arapahoe | Larry Semo, Rachel Kolokoff, Peter Gent |
| 2001-002 | 2001 |
Greeley
| Weld | David Bolton, Doug Faulkner, Peter Gent |
| 2002-016 | 2001 |
Severance area
| Weld | Doug Faulkner |
| 2001-152 | 2001 |
Long Pond and surrounding lakes
| Larimer | Rachel Hopper |
| 2003-096 | 2003 |
Bittersweet Park, Greeley, and Brunner Lake, Broomfield
| Broomfield & Weld | Al Guarente, Roger Linfield, Bill Schmoker, Rachel Hopper, Doug Faulkner |
| 2005-014 | 2005 |
Littleton
| Arapahoe | Tony Leukering, Brandon K Percival, Steve Decker, Doug Faulkner |
| 2005-121 | 2005 |
Fort Collins
| Larimer | Nicholas Komar, Andrew Spencer, Cole Wild, Doug Faulkner |
| 2006-011 | 2006 |
Fort Collins
| Larimer | Doug Faulkner, Larry Semo |
| 2006-186 | 2006 |
Aurora
| Arapahoe | Mary Jane Black, Ellie Jones |
| 2006-156 | 2006 |
Pueblo Reservoir area
| Pueblo | Brandon Percival |
| 2012-016 | 2011 |
Fort Collins
| Larimer | Rachel Hopper |
| 2013-016 | 2011 |
Lake Cheraw
| Otero | Nick Moore |
| 2012-207 | 2012 |
Loveland
| Larimer | Jim Thompson, Jim Thompson, Eric Lutomski, Steven Mlodinow, David Dowell |
| 2013-013 | 2012 |
Jackson Reservoir
| Morgan | Steven Mlodinow |
| 2015-030 | 2015 |
Monte Vista National Wildlife Refuge
| Rio Grande | Ted Floyd, Polly Neldner, Brandon K. Percival |
| 2015-127 | 2015 |
Colorado City and Rye
| Pueblo | David Silverman |
| 2016-104 | 2016 |
Hidden Lake
| Adams | Chris Rurik |
| 2017-004 | 2017 |
Aurora Reservoir
| Arapahoe | Steven Mlodinow |
| 2017-007 | 2017 |
Indian Tree Golf Course
| Jefferson | Doug Faulkner |
| 2018-086 | 2018 |
Timnath Reservoir
| Larimer | Andrew Bankert |
| 2019-012 | 2019 |
Frederick Reservoir and Recreation Area
| Weld | Rachel Hopper |
| 2023-041 | 2023 |
Alamosa River
| Rio Grande | Kathy Mihm Dunning |