The Kuparuk River is a river in Alaska's North Slope that enters a bay on the Beaufort Sea between Beechey Point and Prudhoe Bay. The north-flowing river is about 200 miles long, and its delta is about 3 miles wide. Its Eskimo name appeared on a map drawn in 1901 by a prospector who spelled it Koopowra, which he translated as Big River. Kuukpaaġruk …The Kuparuk River is a river in Alaska's North Slope that enters a bay on the Beaufort Sea between Beechey Point and Prudhoe Bay. The north-flowing river is about 200 miles long, and its delta is about 3 miles wide. Its Eskimo name appeared on a map drawn in 1901 by a prospector who spelled it Koopowra, which he translated as Big River. Kuukpaaġruk can be translated to a "smaller version of a big river".