Scotts Bluff National Monument: see Scottsbluff; National Parks and Monuments (table).

Poplar Bluff, city (1990 pop. 16,996), seat of Butler co., SE Mo., in the Ozark foothills, on the low bluffs of the Black River near the Ark. line; inc. 1870. It is a trade, shipping, and medical center in a fertile farming area. Among its manufactures are transportation equipment; plastic, wood, and paper products; furniture; building materials; flour; and shoes. Nearby are Mark Twain National Forest and Wappapello Dam.

Pine Bluff, city (1990 pop. 57,140), seat of Jefferson co., S central Ark., on the Arkansas River; inc. 1839. It is a port and trade center for an agricultural area and has industries producing metal, wood, and paper products; machinery; electrical equipment; and foods. It is also a research center and the seat of the Univ. of Arkansas at Pine Bluff. Of economic importance to the city is the huge Pine Bluff Arsenal to the north; established during World War II, it is the center of U.S. army chemical, biological, and toxicological research. Pine Bluff has an arts and science center and a civic complex designed by Edward Durell Stone.

Drewry's Bluff, high ground on the southern bank of the James River, E Va., S of Richmond; scene of two engagements in the Civil War. On May 15, 1862, the Confederates, positioned on the bluff, repulsed Union gunboats that were part of Gen. George McClellan's Peninsular campaign. In May, 1864, Union Gen. Benjamin Butler led the Army of the James up the peninsula against Richmond. Butler was defeated at Drewrys Bluff on May 16, 1864, by a greatly inferior Confederate force under Gen. Pierre Beauregard.

Balls Bluff, hill on the south bank of the Potomac River, near Leesburg, Va. In the Civil War, Union troops who had crossed the river were severely repulsed there on Oct. 21, 1861. Dissatisfaction with that defeat and with the general inactivity of the Union armies led to the organization of a joint congressional committee on the conduct of the war.

National monument, western Nebraska, U.S. Established in 1919, it has an area of 5 sq mi (13 sq km). Its focus is a large bluff that rises 800 ft (244 m) above the North Platte River and was a prominent landmark on the Oregon Trail. A museum at the base of the bluff highlights the history of the pioneer travelers.

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