Information: - A ski is a narrow strip of semi-rigid material worn underfoot to glide over snow. Substantially longer than wide and characteristically employed in pairs, skis are attached to ski boots with ski bindings, with either a free, lockable, or partially secured heel. For climbing slopes, ski skins (originally made of seal fur, but now made of synthetic materials) can be attached at the base of the ski. - Groundwater (or ground water) is the water present beneath Earth's surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from, and eventually flows to, the surface naturally; natural discharge often occurs at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology. - A lake is an area of variable size filled with water, localized in a basin, that is surrounded by land, apart from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, and therefore are distinct from lagoons, and are also larger and deeper than ponds, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which are usually flowing. Most lakes are fed and drained by rivers and streams. - Mount Hood, called Wy'east by the Multnomah tribe, is a potentially active stratovolcano in the Cascade Volcanic Arc of northern Oregon. It was formed by a subduction zone on the Pacific coast and rests in the Pacific Northwest region of the United States. It is located about east-southeast of Portland, on the border between Clackamas and Hood River counties. In addition to being Oregon's highest mountain, it is one of the loftiest mountains in the nation based on its prominence. - Eisenbach is a town in the district of Breisgau-Hochschwarzwald in Baden-Wurttemberg in Germany. - A ski resort is a resort developed for skiing, snowboarding, and other winter sports. In Europe, most ski resorts are towns or villages in or adjacent to a ski area a mountainous area with pistes, ski trails and a ski lift system. In North America, it is more common for ski areas to exist well away from towns, so ski resorts usually are destination resorts, often purpose-built and self-contained, where skiing is the main activity. - Snow pertains to frozen crystalline water throughout its life cycle, starting when it precipitates from clouds and accumulates on surfaces, then metamorphoses in place, and ultimately melts, slides or sublimates away. Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes nucleate around particles in the atmosphere by attracting supercooled water droplets, which freeze in hexagonal-shaped crystals. Snowflakes take on a variety of shapes, basic among these are platelets, needles, columns and rime. As snow accumulates into a snowpack, it may blow into drifts. Over time, accumulated snow metamorphoses, by sintering, sublimation and freeze-thaw. Where the climate is cold enough for year-to-year accumulation, a glacier may form. Otherwise, snow typically melts, seasonally, and causes runoff into streams and rivers and recharging groundwater. - Cooper Spur ski area is a ski area located on northeast Mount Hood , Oregon , United States . The resort has one double chair ski lift serving ten runs , and a vertical drop of 110 meters ( 350 ft ) . There are 6.5 kilometers of cross-country skiing trails . The uphill capacity of the lift is 1200 skiers per hour , and the summit rises to 1,326 meters ( 4350 ft ) . The resort encompasses 0.2 km ( 50 acres ) of terrain , and receives an average of 2.5 meters ( 100 inches ) of snow per year . Cooper Spur Mountain Resort has 3.1 km ( 775 acres ) of forest on which condos , log cabins , a restaurant , and a hotel are located . - The Pacific Northwest (in the United States, commonly abbreviated as PNW), sometimes referred to as Cascadia, is a geographic region in western North America bounded by the Pacific Ocean to the west and loosely, by the Rocky Mountains on the east. Though no agreed boundary exists, a common conception includes the U.S. states of Oregon and Washington and the Canadian province of British Columbia. Broader conceptions reach north into Alaska and Yukon, south into far northern California and east to the Continental Divide, thus including Idaho, Western Montana, and western Wyoming. Narrower conceptions may be limited to the northwestern US or to the coastal areas west of the Cascade and Coast mountains. The variety of definitions can be attributed to partially overlapping commonalities of the region's history, geography, society, and other factors. - Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced or sinks due to gravity into the mantle. Regions where this process occurs are known as "subduction zones". Rates of subduction are typically in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. - Cross-country skiing is a form of skiing where skiers rely on their own locomotion to move across snow-covered terrain, rather than using ski lifts or other forms of assistance. Cross-country skiing is widely practised as a sport and recreational activity; however, some still use it as a means of transportation. Variants of cross-country skiing are adapted to a range of terrain which spans unimproved, sometimes mountainous terrain to groomed courses that are specifically designed for the sport. - Snowpack forms from layers of snow that accumulate in geographic regions and high altitudes where the climate includes cold weather for extended periods during the year. Snowpacks are an important water resource that feed streams and rivers as they melt. Therefore, snowpacks are both the drinking water source for many communities and a potential source of flooding (in case of sudden melting). Snowpacks also contribute mass to glaciers in their accumulation zone. - Sintering is the process of compacting and forming a solid mass of material by heat or pressure without melting it to the point of liquefaction. - Skiing is a mode of transport, recreational activity and competitive winter sport in which the participant uses skis to glide on snow. Many types of competitive skiing events are recognized by the International Olympic Committee (IOC), and the International Ski Federation (FIS). - A ski lift is a mechanism for transporting skiers up a hill. Ski lifts are typically a paid service at ski resorts. The first ski lift was built in 1908 by German Robert Winterhalder in Schollach/Eisenbach, Hochschwarzwald. Types of lifts are: - A glacier (or ) is a persistent body of dense ice that is constantly moving under its own weight; it forms where the accumulation of snow exceeds its ablation (melting and sublimation) over many years, often centuries. Glaciers slowly deform and flow due to stresses induced by their weight, creating crevasses, seracs, and other distinguishing features. They also abrade rock and debris from their substrate to create landforms such as cirques and moraines. Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. - A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic explosive eruptions and effusive eruptions, although some have collapsed craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far due to high viscosity. The magma forming this lava is often felsic, having high-to-intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less-viscous mafic magma. Extensive felsic lava flows are uncommon, but have travelled as far as . Given the information, choose the subject and object entities that have the relation of 'instance of'.
A:
cooper spur ski area , ski resort