Ondatra zibethicus By Matt Young June 15, 2015 12:00 MST Ondatra zibethicus – muskrat, Elmer’s Two-Mile Creek, Boulder, Colorado, May, 2015. The muskrat shown here disappeared after the 2013 flood, and I did not see any muskrats again till this spring. Don’t forget to enter the photography contest – 1 week remaining!