Geography
Idaho borders six states and one Canadian province. The states of Washington and Oregon are to the west, Nevada and Utah are to the south, and Montana and Wyoming are to the east. Idaho also shares a short border with the Canadian province of British Columbia to the north. The landscape is rugged with some of the largest unspoiled natural areas in the United States. For example, at 2.3 million acres (930,000 ha), the Frank Church-River of No Return Wilderness Area is the largest contiguous area of protected wilderness in the continental United States. Idaho is a Rocky Mountain state with abundant natural resources and scenic areas. The state has snow-capped mountain ranges, rapids, vast lakes and steep canyons. The waters of the Snake River rush through Hells Canyon, the deepest gorge in the United States. Shoshone Falls plunges down rugged cliffs from a height greater than that of Niagara Falls. The major rivers in Idaho are the Snake River, the Clark Fork/Pend Oreille River, the Clearwater River, and the Salmon River. Other significant rivers include the Coeur d'Alene River, the Spokane River, the Boise River, and the Payette River. The Salmon River empties into the Snake in Hells Canyon and forms the southern boundary of Nez Perce County on its north shore, of which Lewiston is the county seat. The Port of Lewiston, at the confluence of the Clearwater and the Snake Rivers is the farthest inland seaport on the West Coast at 465 river miles from the Pacific at Astoria, Oregon.
Idaho's highest point is Borah Peak, 12,662 ft (3,859 m), in the Lost River Range north of Mackay. Idaho's lowest point, 710 ft (216 m), is in Lewiston, where the Clearwater River joins the Snake River and continues into Washington. The Sawtooth Range is often considered Idaho's most famous mountain range. Other mountain ranges in Idaho include the Bitterroot Range, the White Cloud Mountains, the Lost River Range, the Clearwater Mountains, and the Salmon River Mountains.
Idaho has two time zones, with the dividing line approximately midway between Canada and Nevada. Southern Idaho, including the Boise metropolitan area, Idaho Falls, Pocatello, and Twin Falls, are in the Mountain Time Zone. A legislative error (15 U.S.C. ch. 6 §264) theoretically placed this region in the Central Time Zone, but this was corrected with a 2007 amendment. Areas north of the Salmon River, including Coeur d'Alene, Moscow, Lewiston, and Sandpoint, are in the Pacific Time Zone, which contains less than a quarter of the state's population and land area.
Climate
Idaho has much variation in its climate. Although the state's western border is located about 350 miles (560 km) from the Pacific Ocean, the maritime influence is still felt in Idaho, especially in the winter when cloud cover, humidity, and precipitation are at their maximum extent. This influence has a moderating effect in the winter where temperatures are not as low as would otherwise be expected for a northern state with predominantly high elevations. The maritime influence is least prominent in the eastern part of the state where the precipitation patterns are often reversed, with wetter summers and drier winters, and seasonal temperature differences more extreme, showing a more semi-arid continental climate.
Climate in Idaho can be hot, although extended periods over 98 °F (37 °C) for the maximum temperature are rare, except for the lowest point in elevation, Lewiston, which correspondingly sees very little snow. Hot summer days are tempered by the low relative humidity and cooler evenings during summer months since, for most of the state, the highest diurnal difference in temperature is often in the summer. Winters can be cold, although extended periods of bitter cold weather below zero are unusual. This is what led the railroad tycoon Harriman family to develop the famous ski resort, Sun Valley. Idaho's all-time highest temperature of 118 °F (48 °C) was recorded at Orofino on July 28, 1934; the all-time lowest temperature of −60 °F (−51 °C) was recorded at Island Park Dam on January 18, 1943.