If you know anyone from Eastern Montana, you likely have heard them refer to coulees. In Montana and most of the Western U.S., a coulee is “A deep gulch or ravine with sloping sides, often dry in summer” (AHD s.v. coulee). While coulee means different things in other places (a stream bed or even a bayou or canal in Louisiana and Southern Mississippi, a valley with hills on either side, or a lava flow), I want to focus on the Montana definition of coulee.
Writer Kari Lynn Dell, novelist and Montana resident defines a coulee this way:
It’s smaller than a valley, wider than a ravine, deeper and longer than a draw. In our area they have been carved by creeks into the flat plain left behind after the massive glacial sheets of ice retreated back to the mountains at the end of the last ice age. Since the word is of French origin, I assume we have the early French Canadian trappers to thank for its prevalence, given that they were the first white men to venture into this area.