In Himalayan physiography, what is the outermost range of the Himalayas called?

Introduction / Context:
This question belongs to the topic of the physiographic structure of the Himalayas. The Himalayan mountain system is not a single uniform wall but is composed of several parallel ranges. The outermost range, closest to the plains of northern India, has a specific name that students need to remember for exams related to Indian geography and geology.

Given Data / Assumptions:

• The question asks for the name of the outermost range of the Himalayas.
• The options are Kali, Shiwaliks, Dehradun, Kumaon, and Garhwal.
• We assume the standard division of the Himalayas into Shiwalik (outer), Lesser or Himachal Himalayas (middle), and Greater or Himadri Himalayas (inner).
• We also note that some options refer to regions or valleys, not ranges.

Concept / Approach:
The Himalayas can be divided, from south to north, into the Shiwalik range, the Lesser Himalayas, and the Greater Himalayas. The Shiwaliks are the southernmost and youngest part of the system, formed by the deposition of sediments eroded from the main Himalayas. They lie closest to the plains and consist of low hills with a lot of unconsolidated material. Dehradun is a valley or dun between the Shiwaliks and the Lesser Himalayas, and Kumaon and Garhwal refer to regional sections rather than the name of the outermost range itself.

Step-by-Step Solution:
Step 1: Recall the three fold division of the Himalayas into Shiwaliks, Lesser Himalayas, and Greater Himalayas. Step 2: Identify that Shiwaliks are situated to the south, closest to the plains, and are therefore the outermost range. Step 3: Recognise that Kali is the name of a river or local boundary and not the entire outer range. Step 4: Note that Dehradun is a structural valley, and Kumaon and Garhwal are regional names for parts of the Himalayas, not for the outermost range itself. Step 5: Select Shiwaliks as the correct answer.

Verification / Alternative check:
Any standard textbook on Indian geography illustrates the cross section of the Himalayas and labels the southernmost belt as the Shiwaliks. These hills are described as relatively low, with elevations ranging roughly between a few hundred and about one thousand metres, and are composed mainly of unconsolidated sediments and gravels. The books also explain that duns such as Dehradun are longitudinal valleys between the Shiwaliks and the Lesser Himalayas, confirming that Shiwaliks are the outermost range, not Dehradun.

Why Other Options Are Wrong:
Kali in this context refers to the Kali river or a local boundary and is not the name of a mountain range. Dehradun is a valley that lies between the Shiwaliks and the Lesser Himalayas, so it cannot be the outermost range. Kumaon and Garhwal are regional terms for sections of the Himalayas in Uttarakhand and refer to broader areas, not to the specific outer range, which remains the Shiwaliks in both places. Therefore none of these options can replace the correct name Shiwaliks.

Common Pitfalls:
Students sometimes confuse valley names and regional names with range names, especially when they hear terms like Kumaon Himalaya or Garhwal Himalaya. Another pitfall is to forget the formal three fold division and mix up Lesser Himalayas with Shiwaliks. To avoid confusion, remember that Shiwaliks are the youngest, southernmost, and outermost hills, while the Greater Himalayas form the high snow covered inner core.

Final Answer:
Shiwaliks