United States, Minnesota, Washington, Science Museum Seep North. Marine on St. Croix. T31N, R19W, NW1/4 NE1/4 SW1/4 NE1/4 of Sec. 18. Old channel NW of old Science Museum Seep North. Marine on St. Croix. T31N, R19W, NW1/4 NE1/4 SW1/4 NE1/4 of Sec. 18. Old channel NW of old dam at log cabin; ca. 1.5 mi. S of town.. 031N 19W 18