premise: All along the shoreline are cottonwood trees , which provide shade and great places for brown trout to hide . Because of this , trout in the Colorado River are in abundance . Heading to the Southwestern part of Colorado people will find the Arkansas River , another outstanding location for trout fishing . In fact , the two best times of year to fish this river are in the spring and mid - winter months . Why might brown trout hide in a shade under the cottonwood trees ?
hypothesis: Because the shade provides a warmer place which makes the fish more comfortable .