Clark (more commonly called Keller Ferry) is an unincorporated community at the bottom of the Hellgate Canyon in the U.S. state of Washington.Most buildings in the community are grouped around the Keller Ferry Campground at the south side of the Keller Ferry crossing. There are several businesses, including a car repair shop and a convenience store. The community is located on Lake Roosevelt, just south of the Lake Roosevelt National Recreation Area.Clark Does not appear on maps anymore, but it did at one time.