Rene Harrop's CDC Beetle dry fly produces when hatches are waning.
Beetles at high elevations in the Rocky Mountains generally attain adulthood in the warmer months of mid- to late summer. At the driest time of year, the mobile adults seek habitats close to water, where the vegetation remains lush until all begins to wither with the frost of autumn.
During this period of low water levels and decreased aquatic insect activity, beetles are at their peak. They are active and available along the edges of streams that flow through open terrain.