Martin Falls is the only officially named waterfall which drops over the lofty walls of Grand Coulee and into Banks Lake. The falls occur as Devils Creek, the largest stream which forms a waterfall feeding Banks Lake, plunges over a sheer basalt cliff for 362 feet before impacting a bench and veiling a final 46 feet over a lower tier. However, given the dry climate in this part of the state and despite agricultural activities in the catchment basin upstream, the falls only flow for a few months out of the year, usually running dry by late April or early May in abnormally wet years.
- Martin Falls is the Official name of this waterfall.
Martin Falls is found adjacent to Steamboat Rock along the shores of Banks Lake in Grand Coulee. The falls can be seen next to Highway 155 about 1 1/3 miles north of the main entrance to Steamboat Rock State Park, or a little over 2 miles south of the Northrup Point picnic area.