The document describes the four parallel mountain ranges that make up the Himalayas from south to north: the Siwalik Ranges, Lesser Himalayas, Great Himalayas, and Trans-Himalayas. The Siwalik Ranges are the outermost and lowest hills, averaging 3,000-4,000 feet in elevation. North of the Siwaliks are the Lesser Himalayas ranging from 11,900-15,100 feet. The Great Himalayas contain the highest peaks such as Everest and Kanchenjunga averaging over 20,000 feet. The northernmost Trans-Himalayas in Tibet are bounded by mountain ranges and the Brahmap

1. Consists of
Four Parallel Ranges.

3. The Shiwalik Ranges.
Siwalik Range, also called Siwalik Hills or Outer
Himalayas, Siwalik also spelled Shiwalik, sub-
Himalayan range of the northern Indian
subcontinent. It extends west-northwestward for
more than 1,000 miles (1,600 km) from the Tista
River in Sikkim state, northeastern India,
through Nepal, across northwestern India, and
into northern Pakistan. Though only 10 miles (16
km) wide in places, the range has an average
elevation of 3,000 to 4,000 feet (900 to 1,200
metres). It rises abruptly from the plain of
the Indus and Ganges (Ganga) rivers (south) and
parallels the main range of the Himalayas(north),
from which it is separated by valleys. The Siwaliks
are sometimes considered to include the
southern foothills of the Assam Himalayas, which
extend eastward for 400 miles (640 km) across
southern Bhutan to the bend of the Brahmaputra
River.

4. The Lesser Himalayas.
To the north of the Shiwaliks and separated
from them by a fault zone, the Lesser
Himalayas (also called the Lower or Middle
Himalayas) rise to heights ranging from 11,900
to 15,100 feet (3,600 to 4,600 metres). Their
ancient name is Himachal (Sanskrit: hima,
“snow,” and acal, “mountain”). These
mountains are composed of both ancient
crystalline and geologically young rocks,
sometimes in a reversed stratigraphic sequence
because of thrust faulting. The Lesser Himalayas
are traversed by numerous deep gorges formed
by swift-flowing streams (some of them older
than the mountains themselves), which are fed
by glaciers and snowfields to the north.

5. Himadri.
Great Himalayas, also called Higher
Himalayas or Great Himalaya Range, highest
and northernmost section of
the Himalayan mountain ranges. It extends
southeastward across northern Pakistan,
northern India, and Nepal before trending
eastward across Sikkim state (India)
and Bhutan and finally turning northeastward
across northern Arunachal Pradesh state (India);
throughout nearly all of its length it adjoins to
the north the southern Tibet Autonomous
Region of China. The range’s total length is some
1,400 miles (2,300 km), and it has an average
elevation of more than 20,000 feet (6,100
metres). The Great Himalayas contain many of
the world’s tallest peaks, including (from west to
east)Nanga Parbat, Annapurna, Mount Everest,
and Kanchenjunga.

6. Trans Himalayas.
Trans-Himalayas, eastward continuation of the most northerly ranges of
the Himalayas in the southern part of the Tibet Autonomous Region of China. It
consists of an ill-defined mountain area about 600 miles (1,000 km) long and 140
miles (225 km) wide in the centre, narrowing to a 20-mile (32-km) width at the
eastern and western ends. The Trans-Himalayas, mainly composed of granites and
volcanic rocks of Neogene and Paleogene age (i.e., about 2.6 to 65 million years old),
are bounded by the Kailas (southwest), Nganglong Kangri (north),
and Nyainqêntanglha (southeast) mountain ranges and by the Brahmaputra (Yarlung
Zangbo) River (south). Unlike the main Himalayas, the mountains are not divided by
deep river gorges and lack a definite alignment. Passes average 17,500 feet (5,330
metres) in height, with the highest being Chargoding Pass (19,308 feet [5,885
metres]). The first recorded European sighting of the mountains was that of the
Swedish explorer Sven Anders Hedin in 1906.