Fergus (FUHR-guhs), county (4,350 sq mi/11,267 sq km; 1990 pop. 12,083), central Mont.; Lewistown; 47°16'N 109°13'W. Irrigated agr. region, mountainous in S; drained by Judith R., bounded N by Missouri R., including part of Upper Missouri Natl. Wild and Scenic River; Arrow Creek forms W boundary. Agr. (grain, wheat, barley, oats, hay; cattle, sheep, hogs). Part of Charles M. Russell Natl. Wildlife Refuge in NE; sect. of Lewis and Clark Natl. Forest in S. Formed 1886. Present boundaries est. 1925.
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