| | Acc. No. | Year | Location | County | Observers |
| 2000-164 | 2000 |
Horseshoe Lake
| Larimer | David Leatherman, Larry Semo, Rachel Hopper, Joe Mammoser, Larry Norris, Ric Olson, Tony Leukering |
| 2014-008 | 2014 |
Aurora Reservoir
| Arapahoe | David Dowell, Kris Petersen, Steven Mlodinow |
| 2022-038 | 2022 |
Boyd Lake State Park
| Larimer | Josh Bruening, Adrian Lakin, Sue Riffe |