| | Acc. No. | Year | Location | County | Observers |
| N-19-77 | 1977 |
CRs 6 & 61
| Weld | Jack Reddall, Robert Andrews, Mildred Snyder |
| 2003-018 | 2002 |
Lake Meredith
| Crowley | Stan Oswald, Rachel Hopper, Larry Semo, Tony Leukering, Peter Gent |
| 2006-135 | 2006 |
Evilsizer Lake area
| Lincoln | Bill Maynard, Brian Gibbons |
| 2008-042 | 2008 |
Boulder Reservoir
| Boulder | Bill Kaempfer, Bill Schmoker, David Waltman, Doug Faulkner, Nathan Pieplow, Nick Komar, Peter Gent, Rachel Hopper, Tom Wilberding |
| 2018-043 | 2018 |
Queens Reservoirs (Neeskah Reservoir area)
| Kiowa | David Dowell |