• You should spend about 20 minutes on Questions 1-13 which are based on Reading Passage 1 below

A. The Columbia River Basin is North America's fourth largest, draining about 250, 000 square miles and extending throughout the Pacific Northwest and into Canada. There are over 250 reservoirs and around 150 hydroelectric projects in the basin, including 18 main stem dams on the Columbia and its main tributary, the Snake River. The US Army Corps of Engineers operates nine of ten major federal projects on the Columbia and Snake rivers, and Dworshak Dam on the Clearwater River, Libby Dam on the Kootenai River, and Albeni Falls Dam on the Pend Oreille River. The federal projects are a major source of power in the region, and provide flood control, navigation, recreation, fish and wildlife, municipal and industrial water supply, and irrigation benefits. B. The Columbia River Basin provides habitat for five species of salmon (chinook, coho, chum, sockeye and pink), steelhead, shad, smelt and lamprey. Salmon hatch in fresh water rivers and tributaries where they rear for a year or two. They then migrate to and mature in the ocean and return to their place of origin as adults to spawn. Salmon live two to five years in the ocean before returning to spawning areas. A number of factors have contributed to the decline of salmon stocks in the Columbia and Snake River Basin. Overharvesting in the late 1800s into the early 1900s, effects on habitat from farming, cattle grazing, mining, logging, road construction, and industrial pollution, and the complex of tributary and main stem dams all have had an impact. A variety of ocean conditions including currents, pollution, temperature changes, and nutrient base affect salmon survival. Dams clearly have had a significant impact, particularly those that eliminated access to fresh water habitat (preventing adult fish from returning to spawn), and those through which fish passage is provided but at reduced levels from natural conditions.