In geography a canyon is a narrow, deep gorge, with steep sides, cut by a river through soft rock in a dry region. The biggest and best known is the Grand Canyon of the Colorado River, USA. Research Canyon
The chinook is the warm dry wind at the eastern base of the Rocky Mountains, and presents the same features as the fohn winds of Switzerland. The chinook winds descend from the Rockies, and while they are chiefly found in Montana and Wyoming, they also extend from the southern part of Colorado up into Canada as far as the Arctic circle. The high temperatures are confined to the valleys, and occur in streaks or pockets so that a traveller frequently passes suddenly from a very warm to a very cold atmosphere. Research Chinook
Allosaurus was the biggest and fiercest carnivorousdinosaur of the Jurassic period. It was 15m tall, about 12 m long and weighed about three tons. Remains of Allosaurus were first discovered in Colorado in 1869 and then in 1877 more were discovered by Dr O C Marsh. Research Allosaurus
Apatosaurus - also known as Brontosaurus - was a huge, plant-eating dinosaur, of the suborder Sauropoda, that lived in the Late Jurassic period, more than 140 million years ago. The name Brontosaur comes from the Greek bronte, 'thunder' and sauros, 'lizard', and implies that the animal shook the ground when it walked. It was about 21 metres long and weighed up to 30 metric tons. Its body was relatively short and thick, the neck long and slender, the tail large and strong, and the four limbs massive and of nearly equal length. The first brontosaurus skeleton was discovered in 1879 in Colorado by the American palaeontologist Othniel Charles Marsh. It lacked a skull, so Marsh gave it a blunt, small skull found nearby. Scientists confirmed in 1979 that the skull was that of another sauropod, Camarasaurus. The Apatosaurus true skull was found to have a longer snout and longer, finer teeth. Research Apatosaurus
The beaver (Castor) is the only genus of the family Castoridae. The family contains a single genus, Castor, with two species: Castor canadensis, found in the New World, and Castor fibre, found in the Old World. Both species are semi-aquatic rodents noted for the building of dams. The two species differ chiefly in the shape of the nasal bones and are so much alike that some authorities consider them to be varieties of the same species. They are large rodents; the average adult beaver weighs about 16 kg, but specimens as heavy as 40 kg have been found, and some extinct beavers were almost bear- like in size. The beaver is usually about 76 centimetres long and stands less than 30 centimetres high, with a broad, flat, scaly tail about 25 centimetres long.
The body is plump, the back arched, the neck thick, the hind feet webbed, and all the digits clawed. The fur is usually reddish- brown above and lighter or greyish below. The eyes are small and the nostrils closable. The skull is massive, with marked ridges for fixing the muscles that work the jaws. The two front teeth on either jaw are like those of other rodents, wearing away more rapidly behind so as to leave a sharp, enamelled chisel edge. With these the beaver can cut down large trees. It usually selects trees five to 20 centimetres in diameter, but it can fell trees with diameters as large as 76 cm.
Beavers have a pair of anal scent glands, called castors, that secrete a musk-like substance called castoreum, probably for marking territories. The animals tend to be monogamous and have a life span of 20 years or more. The female has one litter a year, usually of two to four young.
Beavers are social animals and in areas where food is abundant and the locality secluded, the number of families in a beaver community can be rather large. The so-called beaver lodge is a unique structure. Three distinct kinds exist, their differences depending on whether they are built on islands, on the banks of ponds, or on the shores of lakes. The island lodge consists of a central chamber, with its floor a little above the level of the water, and with two entrances. One of these, the 'wood entrance', is a straight incline rising from the water, opening into the floor of the hut. The other approach, the 'beaver entrance', is more abrupt in its descent to the water.
The lodge itself is an oven-shaped house of sticks, grass, and moss, woven together and plastered with mud. The room inside is carpeted with bark, grass, and wood chips, sometimes with special store rooms adjoining. The pond lodge is built either a short way back from the edge of the bank, or partly hanging over it, with the front wall built up from the bottom of the pond. The lakelodge is built on the shelving shores of lakes. Dams are used by beavers to widen the area and increase the depth of water around their homes and are constructed either of sticks and poles or more firmly and solidly of mud, brushwood, and stones. As time goes by the beaver repairs and adds to the dam. Floating material lodges there, and vegetation growing on the top adds its roots to the strength of the dam. Frequently the beaver builds a smaller dam downstream in order to back up some water against the original dam and thus decrease the pressure of water on it from the other side. The dams are about 1.5 metres high, usually more than three metres wide at the base, and narrow at the top. A beaver dam more than 300 metres long was found in Rocky Mountain National Park, Colorado.
Beaver ponds eventually fill with sediment, and the animals move to a new location. The abandoned area becomes good meadowland. Beaver dams also help control runoff. Although the beaver is a powerful swimmer, it has difficulty dragging over the ground the logs and branches it needs for building and for food. Colonies of beavers therefore often dig canals from the pond to a grove of trees. Such canals are up to one metre wide and deep and often a few hundred metres long. The timber is then readily floated down the canal toward the pond.
Beavers have long been exploited for their fur, and for many years during the 18th and 19th centuries hundreds of thousands of beaver skins were exported to Europe from North America annually. The animals were also sometimes destroyed because of the damage they did to forests and the flooding occasionally caused by dams. Ceaseless slaughter led to near extinction of beavers in both Europe and North America. The beaver is almost extinct in Europe, but is becoming re-established in Canada and in protected areas of the USA. Research Beaver
The Colorado Beetle (Leptinotarsa decemlineata) is a North American leaf beetles (Chrysomelidae) that attacks potatoes. It is a striped beetle resembling a ladybird in shape. It reached Europe in 1877 and were wiped out, but reappeared in 1922 and gained a footing in France. Since 1936 they regularly invaded Germany and since 1948 Germany has been plagued by them, but has so far been prevented from establishing itself in England. Originally the Colorado Beetle in its native environment fed upon nightshades, but with the cultivation of potatoes developed a preference for them. Research Colorado Beetle
The Colorado Ranger (or Rangerbred Horse) is an American bred of riding and cow-work horse standing between 14.2 and 16 hands high and occurring in many colours, often spotted. The breed originates from two stallions presented to General U S Grant in 1878 and subsequently lent out for stud. Research Colorado Ranger
The Great Egret (Casmerodius albus) is an American, large all-white heron with a long yellow bill and long black legs of the order Grallae, family Ardeidae. It is a fairly common permanent resident near and in a wide variety of wetlands habitats of southern California and nests throughout most of California; in southern California it is especially common at Salton Sea, and the Colorado River. Research Great Egret
Ornithomimus was a dinosaur of the Cretaceous period. Ornithomimus was a medium-sized animal, about four metres long, half its length being taken by its tail, that walked on its hind legs and was devoid of teeth but instead had a horny beak and probably fed in a manner similar to modern birds, using its hands to tear and break leaves, fruit, insects, lizards and small animals into pieces which could then be swallowed. The first remains of Ornithomimus were discovered in 1889 near Denver, Colorado, USA. Ten species of Ornithomimus have been discovered. Research Ornithomimus
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