Yukon Territory in the context of History of the Northwest Territories

Prospecting is the first stage of the geological analysis (followed by exploration) of a territory. It is the search for minerals, fossils, precious metals, or mineral specimens. It is also known as fossicking.

Traditionally prospecting relied on direct observation of mineralization in rock outcrops or in sediments. Modern prospecting also includes the use of geologic, geophysical, and geochemical tools to search for anomalies which can narrow the search area. Once an anomaly has been identified and interpreted to be a potential prospect direct observation can then be focused on this area.

A complex volcano, also called a compound volcano or a volcanic complex, is a mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock. They may form due to changes in eruptive habit or in the location of the principal vent area on a particular volcano. Stratovolcanoes can also form a large caldera that gets filled in by a lava dome, or else multiple small cinder cones, lava domes and craters may develop on the caldera's rim.

Although a comparatively unusual type of volcano, they are widespread in the world and in geologic history. Metamorphosed ash flow tuffs are widespread in the Precambrian rocks of northern New Mexico, which indicates that caldera complexes have been important for much of Earth's history. Yellowstone National Park is on three partly covered caldera complexes. The Long Valley Caldera in eastern California is also a complex volcano; the San Juan Mountains in southwestern Colorado are formed on a group of Neogene-age caldera complexes, and most of the Mesozoic and Cenozoic rocks of Nevada, Idaho, and eastern California are also caldera complexes and their erupted ash flow tuffs. The Bennett Lake Caldera in British Columbia and the Yukon Territory is another example of a Cenozoic (Eocene) caldera complex.

The Alaska Range is a relatively narrow, 600-mile-long (970-kilometer) mountain range in the southcentral region of the U.S. state of Alaska, from Lake Clark at its southwest end to the White River in Canada's Yukon Territory in the southeast. Denali, the highest mountain in North America, is in the Alaska Range. The range is part of the American Cordillera.

The Alaska Range is one of the highest mountain ranges in the world, after the Himalayas and the Andes.

The Brooks Range (Gwich'in: Gwazhał) is a mountain range in far northern North America stretching some 700 miles (1,100 km) from west to east across northern Alaska into Canada's Yukon Territory. Reaching a peak elevation of 8,976 feet (2,736 m) on Mount Isto, the range is believed to be approximately 126 million years old.

In the United States, these mountains are considered a subrange of the Rocky Mountains, whereas in Canada they are considered separate, as the northern border of the Rocky Mountains is considered to be the Liard River far to the south in the province of British Columbia.

The Coast Mountains (French: La chaîne Côtière) are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia south to the Fraser River. The mountain range's name derives from its proximity to the sea coast, and it is often referred to as the Coast Range. The range includes volcanic and non-volcanic mountains and the extensive ice fields of the Pacific and Boundary Ranges, and the northern end of the volcanic system known as the Cascade Volcanoes. The Coast Mountains are part of a larger mountain system called the Pacific Coast Ranges or the Pacific Mountain System, which includes the Cascade Range, the Insular Mountains, the Olympic Mountains, the Oregon Coast Range, the California Coast Ranges, the Saint Elias Mountains and the Chugach Mountains. The Coast Mountains are also part of the American Cordillera—a Spanish term for an extensive chain of mountain ranges—that consists of an almost continuous sequence of mountain ranges that form the western backbone of North America, Central America, South America and Antarctica.

The Coast Mountains are approximately 1,600 kilometres (1,000 mi) long and average 300 kilometres (190 mi) in width. The range's southern and southeastern boundaries are surrounded by the Fraser River and the Interior Plateau while its far northwestern edge is delimited by the Kelsall and Tatshenshini Rivers at the north end of the Alaska Panhandle, beyond which are the Saint Elias Mountains, and by Champagne Pass in the Yukon Territory. Covered in dense temperate rainforest on its western exposures, the range rises to heavily glaciated peaks, including the largest temperate-latitude ice fields in the world. On its eastern flanks, the range tapers to the dry Interior Plateau and the subarctic boreal forests of the Skeena Mountains and Stikine Plateau.

The Teslin River is a river in southern Yukon Territory and northwestern British Columbia, Canada, that flows 632 kilometres (393 mi) from its source south of Teslin Lake to its confluence with the Yukon River.

During the Klondike Gold Rush of 1896–99, the river became a popular route to the Klondike gold fields near Dawson City with the stampeders who had crossed the Coast Mountains by routes such as the Chilkoot Trail or the White Pass trail.

The Whitehorse rapids were rapids on the Yukon River in Canada's Yukon Territory, named for their supposed resemblance to the mane of a charging white horse. The rapids formed where the Yukon River flows across and cuts down through lava flows of the Miles Canyon basalt. These rapids presented a major navigational obstacle on the Yukon River during the Klondike Gold Rush, and lent their name to the nearby town of Whitehorse.

The Whitehorse dam, constructed in 1957–1958, submerged the rapids beneath the newly created Schwatka Lake.

The Boundary Ranges, also known in the singular and as the Alaska Boundary Range, are the largest and most northerly subrange of the Coast Mountains. They begin at the Nass River, near the southern end of the Alaska Panhandle in the Canadian province of British Columbia and run to the Kelsall River, near the Chilkoot Pass, beyond which are the Alsek Ranges of the Saint Elias Mountains, and northwards into the Yukon Territory flanking the west side of the Yukon River drainage as far as Champagne Pass, north of which being the Yukon Ranges. To their east are the Skeena Mountains and Stikine Plateau of the Interior Mountains complex that lies northwest of the Interior Plateau; the immediately adjoining subregion of the Stikine Plateau is the Tahltan Highland. To their northeast is the Tagish Highland, which is a subregion of the Yukon Plateau. Both highlands are considered in some descriptions as included in the Coast Mountains. The Alexander Archipelago lies offshore and is entirely within Alaska.

The Boundary Ranges include several large icefields, including the Juneau Icefield, between the Alaskan city of the same name and Atlin Lake in B.C.; and the Stikine Icecap, which lies between the lower Stikine River and the Whiting River. Some of the highest mountains in the Boundary Ranges are: Mount Ratz, 3,090 m (10,138 ft); Chutine Peak, 2,910 m (9,547 ft); and Devils Thumb, 2,766 m (9,075 ft), all in the Stikine Icecap region; and Devils Paw, 2,593 m (8,507 ft), in the Juneau Icefield. (Other peaks in the Stikine Icecap are higher than 2,600 m (8,530 ft), but they have relatively low topographic prominence.)