Which one of the following mountain ranges is spread over only one State in India ?

1. Physiographic Divisions of the Peninsular Plateau (basic)

The Peninsular Plateau is often described as a massive, irregular triangle that forms the heart of the Indian landmass. Unlike the high, jagged peaks of the Himalayas, this region is a tableland characterized by broad, shallow valleys and rounded hills. Geologically, it is one of the oldest and most stable parts of the Earth, having formed from the breaking and drifting of the Gondwana land. It is primarily composed of ancient crystalline, igneous, and metamorphic rocks CONTEMPORARY INDIA-I, Geography Class IX, p.12.

The plateau's boundaries define the shape of peninsular India: the Delhi ridge in the northwest (an extension of the Aravallis), the Rajmahal hills in the east, the Gir range in the west, and the Cardamom hills in the far south. Interestingly, the plateau extends even further northeast into the Shillong and Karbi-Anglong regions, though it is separated from the main block by a geological fault INDIA PHYSICAL ENVIRONMENT, Geography Class XI, p.12.

For easier study, we divide this vast region into two primary segments based on the flow of the Narmada River:

• The Central Highlands: The portion lying north of the Narmada, covering a large part of the Malwa plateau. It is bounded by the Vindhyan range to the south and the Aravallis to the northwest CONTEMPORARY INDIA-I, Geography Class IX, p.12.
• The Deccan Plateau: The triangular landmass lying south of the Narmada. It is higher in the west and slopes gently eastward, leading to the flow of major rivers like the Godavari and Krishna toward the Bay of Bengal.

Sources: CONTEMPORARY INDIA-I, Geography Class IX, Physical Features of India, p.12; INDIA PHYSICAL ENVIRONMENT, Geography Class XI, Structure and Physiography, p.12

2. Old Fold Mountains vs. Block Mountains (intermediate)

To understand the relief of India, we must distinguish between how mountains are built. Fold Mountains are created by horizontal compressional forces that crumple the Earth's crust into folds, much like a rug bunching up when pushed from the sides. When these mountains formed hundreds of millions of years ago (during the Precambrian or Paleozoic eras), they are termed Old Fold Mountains. Over eons, wind and water wear them down, resulting in a 'relict' or 'residual' appearance with rounded peaks and lower elevations Physical Geography by PMF IAS, Types of Mountains, p.135. The Aravalli Range is the classic Indian example; once as mighty as the Himalayas, it is now a highly denuded range stretching 800 km from Delhi to Gujarat, with its highest point, Guru-Sikhar, reaching only 1,722 m Geography of India, Physiography, p.54.

In contrast, Block Mountains are formed by vertical displacement due to faulting. When the crust cracks under tension or compression, large blocks of earth are either raised (forming a Horst or Block Mountain) or subsided (forming a Graben or Rift Valley). In India, the Vindhya and Satpura ranges are prime examples of this phenomenon Physical Geography by PMF IAS, Types of Mountains, p.133. The Satpura range, which includes the Rajpipla, Mahadev, and Maikal hills, stands as a structural block between the Narmada and Tapti rift valleys, with Dhupgarh (1,350 m) being its highest summit Geography of India, Physiography, p.55.

Feature	Old Fold Mountains	Block Mountains
Primary Force	Compression (Folding)	Tension/Faulting (Fracturing)
Appearance	Rounded peaks, gentle slopes (due to age)	Flat tops, steep 'scarp' faces
Indian Example	Aravalli Range	Satpura and Vindhya Ranges

Sources: Geography of India, Physiography, p.54-55; Physical Geography by PMF IAS, Types of Mountains, p.133-135

3. The Sahyadri and Western Ghats Extension (intermediate)

The Western Ghats, often referred to by the Sanskrit name Sahyadri, represent one of the most significant geographical features of the Indian peninsula. Far from being a simple line of hills, they form a massive 'Great Escarpment' running parallel to the western coast for approximately 1,600 km. This range begins just south of the Tapi river in Gujarat and stretches continuously down to Kanyakumari at the southern tip of India Geography of India, Majid Husain, Physiography, p.58. Geologically, these are block mountains created by the downward warping of a portion of land into the Arabian Sea, which explains why their western slopes are incredibly steep while the eastern slopes transition gently into the Deccan Plateau Geography of India, Majid Husain, Physiography, p.58.

One of the most important aspects for your preparation is understanding the multi-state extension of this range. Unlike smaller internal ranges (such as the Ajanta or Balaghat ranges which are confined to a single state), the Sahyadri is a cross-border giant. It traverses six states: Gujarat, Maharashtra, Goa, Karnataka, Tamil Nadu, and Kerala Geography of India, Majid Husain, Natural Vegetation and National Parks, p.55. Because of its vast length, it is known by various local names that you should memorize: Sahyadri in Maharashtra, Nilgiri hills in Karnataka and Tamil Nadu, and the Anaimalai and Cardamom hills further south in Kerala INDIA PHYSICAL ENVIRONMENT, NCERT Class XI, Structure and Physiography, p.12.

Beyond its physical presence, the range acts as the primary watershed of Peninsular India. All major rivers of the plateau—the Godavari, Krishna, and Kaveri—originate in these heights and flow eastward. Due to its unique climate and isolation, it is recognized as one of the world's eight 'hottest hotspots' of biological diversity and a UNESCO World Heritage site Geography of India, Majid Husain, Natural Vegetation and National Parks, p.55.

Sources: Geography of India, Majid Husain, Physiography, p.58; Geography of India, Majid Husain, Natural Vegetation and National Parks, p.55; INDIA PHYSICAL ENVIRONMENT, NCERT Class XI, Structure and Physiography, p.12

4. Drainage Systems of Central and Peninsular India (intermediate)

To understand the drainage of Peninsular India, we must first recognize that it is a much older and more stable system compared to the Himalayan rivers. While Himalayan rivers are 'youthful' and still carving deep gorges, Peninsular rivers flow through broad, shallow, and largely-graded valleys, indicating they have reached a stage of maturity INDIA PHYSICAL ENVIRONMENT, Geography Class XI (2025 ed.), Chapter 3, p.23. The defining feature of this system is the Western Ghats (Sahyadri), which runs close to the western coast and acts as the primary water divide. This divide dictates that most major rivers—like the Godavari, Krishna, and Kaveri—originate in the West and flow eastward into the Bay of Bengal due to the gentle eastward tilt of the Peninsular plateau CONTEMPORARY INDIA-I, Geography, Class IX, Chapter 3, p.21. However, there are significant exceptions to this eastward flow. The Narmada and Tapi are the only major long rivers that flow westward into the Arabian Sea. They do not follow the general tilt of the plateau because they flow through rift valleys formed due to tectonic disturbances. For instance, the river Tapi rises in the Satpura Range and flows westward, squeezed into a constricted rift valley between the Satpura Range to its north and the Ajanta Range to its south Geography of India, Majid Husain, Chapter 3, p.20. Unlike the east-flowing rivers that form massive deltas, these west-flowing rivers form estuaries at their mouths.

Feature	East-Flowing Rivers	West-Flowing Rivers
Examples	Mahanadi, Godavari, Krishna, Kaveri	Narmada, Tapi, Mahi, Sabarmati
Mouth Type	Large Deltas	Estuaries
Drainage Basin	Relatively larger (e.g., Godavari is the largest)	Relatively smaller
Geological Setting	Follow the general plateau tilt	Flow through Tectonic Rift Valleys

It is also worth noting that the northern part of the Peninsula contributes to the Ganga river system. Rivers like the Chambal, Betwa, Ken, and Son originate in the central highlands but flow northwards, showing that the drainage of the Peninsula is complex and influenced by various mountain ranges INDIA PHYSICAL ENVIRONMENT, Geography Class XI (2025 ed.), Chapter 3, p.23.

Sources: INDIA PHYSICAL ENVIRONMENT, Geography Class XI (2025 ed.), Chapter 3: Drainage System, p.23; CONTEMPORARY INDIA-I, Geography, Class IX, Chapter 3: Drainage, p.21; Geography of India, Majid Husain, Chapter 3: The Drainage System of India, p.20; Geography of India, Majid Husain, Chapter 3: The Drainage System of India, p.4

5. Climatic Influence: Orographic Rain and Rain-Shadows (exam-level)

To understand why certain parts of India are lush green while others just a few kilometers away are parched, we must look at Orographic Rainfall. The term 'orographic' comes from the Greek word oros (mountain). When moisture-laden winds, such as the Arabian Sea branch of the Southwest Monsoon, encounter a mountain range like the Sahyadris (Western Ghats), they are forced to rise. As this air ascends the slopes (typically between 900–1200 m), it undergoes adiabatic cooling. The moisture condenses, forming clouds that pour heavy rain—ranging from 250 cm to over 400 cm—on the windward side INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.), Climate, p.35.

Once the clouds cross the summit, the story changes completely. The air, now depleted of much of its moisture, begins to descend the opposite slope. As it sinks, the air compresses and heats up, a process that increases its capacity to hold moisture and thus reduces relative humidity. This creates the Rain-Shadow Area on the leeward side. In India, this region encompasses vast tracts of the Deccan Plateau, including parts of Maharashtra (Vidarbha), Karnataka, and Telangana. Here, the average annual rainfall often drops below 60–75 cm, making these regions chronically drought-prone and subject to high rainfall variability Geography of India, Majid Husain, Climate of India, p.37.

Feature	Windward Side (e.g., Konkan Coast)	Leeward Side (e.g., Vidarbha/Rayalaseema)
Air Movement	Rising and cooling (Ascending)	Sinking and warming (Descending)
Rainfall Volume	Very Heavy (250–400 cm)	Scanty (Less than 75 cm)
Climate Type	Humid / Tropical Wet	Semi-arid / Drought-prone

However, nature has its exceptions. While these rain-shadow regions are generally dry, they are not permanently devoid of water. During the cyclone season, these semi-arid regions in South India—such as Rayalaseema and Telangana—often receive copious rainfall when tropical cyclones move inland from the Bay of Bengal Physical Geography by PMF IAS, Tropical Cyclones, p.376. Understanding this balance is crucial for Indian agriculture, as even a small shift in monsoon patterns or condensation nuclei (pollution) can drastically alter these regional micro-climates Physical Geography by PMF IAS, Earths Atmosphere, p.274.

Sources: INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.), Climate, p.35; Geography of India, Majid Husain, Climate of India, p.37; Physical Geography by PMF IAS, Tropical Cyclones, p.376; Physical Geography by PMF IAS, Earths Atmosphere, p.274

6. Minor Hill Ranges of the Deccan Plateau (exam-level)

The Deccan Plateau is not a monolithic block of land; rather, it is a complex mosaic of various plateaus and internal hill ranges. While the Western Ghats (Sahyadri) and Eastern Ghats form its outer edges, the interior of the plateau is crisscrossed by several minor hill ranges that often act as local water divides and cultural landmarks CONTEMPORARY INDIA-I, Physical Features of India, p.12.

One of the most distinct features of these minor ranges is their geographical distribution. While major systems like the Satpuras or the Sahyadri are trans-boundary (stretching across multiple states), many minor ranges are entirely confined to a single state. A prime example is the Ajanta Range. Located in Maharashtra, it is famous for its 30 volcanic rock-cut caves, which served as a major center for Buddhist mural paintings and sculpture History, Cultural Development in South India, p.128. Similarly, the Harishchandra Range is an internal range in southern Maharashtra, stretching through the districts of Pune and Osmanabad Geography of India, Physiography, p.60.

Understanding these ranges requires a look at their physical and economic significance. For instance, the Kudremukh Range in Karnataka is not just a scenic height but a vital source of iron ore, while Kalsubai stands as the highest peak in Maharashtra, located within the Western Ghats complex Geography of India, Physiography, p.60. These hills influence local rainfall patterns and are often the site of ancient forts and religious shrines, making them integral to the regional identity of the Deccan.

Range/Peak	State Location	Key Significance
Ajanta Range	Maharashtra	Famous for UNESCO World Heritage Buddhist caves.
Harishchandra	Maharashtra	Local water divide; contains degraded forest covers.
Kudremukh	Karnataka	Named for its "horse-face" shape; rich in iron ore deposits.
Kalsubai	Maharashtra	The highest point in the Sahyadris within Maharashtra (1646m).

Sources: CONTEMPORARY INDIA-I, Geography, Class IX . NCERT(Revised ed 2025), Physical Features of India, p.12; History, class XI (Tamilnadu state board 2024 ed.), Cultural Development in South India, p.128; Geography of India, Majid Husain (McGrawHill 9th ed.), Physiography, p.60

7. State-wise Mapping of Indian Mountain Ranges (exam-level)

When studying the physiography of India, it is crucial to distinguish between trans-boundary ranges (those crossing multiple states) and localized ranges (those confined to a single state). Most major mountain systems in India are multi-state due to their sheer length. For instance, the Aravalli Range is a classic multi-state feature, stretching approximately 800 km from Delhi, through Haryana and Rajasthan, down to Palanpur in Gujarat Exploring Society: India and Beyond, NCERT Class VII, p.15. Similarly, the Vindhyan Range acts as a massive latitudinal divider, stretching nearly 1,050 km from Gujarat and Rajasthan in the west all the way to Sasaram in Bihar in the east Majid Husain, Geography of India, Physiography, p.54.

The Satpura Range is also a multi-state complex, composed of the Rajpipla Hills, Mahadev Hills, and the Maikal Range, spanning across Gujarat, Maharashtra, Madhya Pradesh, and Chhattisgarh Majid Husain, Geography of India, Physiography, p.55. In contrast, several smaller hill ranges in the Deccan Plateau are entirely contained within the administrative borders of a single state. Notable examples include the Ajanta Range, Balaghat Range, and Harishchandra Range, all of which are situated exclusively within Maharashtra. Identifying these localized ranges is a frequent requirement in mapping-based exam questions.

Mountain Range	Extent (States/UTs Covered)	Type
Aravalli	Gujarat, Rajasthan, Haryana, Delhi	Multi-State
Western Ghats (Sahyadri)	Gujarat, Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu	Multi-State
Vindhya	Gujarat, Rajasthan, Madhya Pradesh, Uttar Pradesh, Bihar	Multi-State
Ajanta	Maharashtra	Single-State

Understanding this spatial distribution helps in visualizing how these ranges influence regional climates. For example, the Aravallis act as a natural barrier that prevents the eastward expansion of the Thar Desert into the fertile plains of Haryana and Delhi Exploring Society: India and Beyond, NCERT Class VII, p.15. Similarly, the Bundelkhand Upland (part of the Vindhyachal Plateau) creates a distinct geographic zone across the borders of Uttar Pradesh and Madhya Pradesh, covering districts like Jhansi and Tikamgarh Majid Husain, Geography of India, Physiography, p.54.

Sources: Exploring Society: India and Beyond, NCERT Class VII, Geographical Diversity of India, p.15; Geography of India, Majid Husain, Physiography, p.54-55

8. Solving the Original PYQ (exam-level)

Having explored the Physiography of India, you can now apply your knowledge of spatial distribution to this classic UPSC question. The core concept here is the distinction between major mountain systems, which are tectonic or structural features spanning vast distances, and localized hill ranges that are often sub-units of larger plateaus. While your previous lessons focused on the geological origin of the Peninsular Plateau, this question tests your ability to visualize the political map of India superimposed over its physical features.

To arrive at the correct answer, you must evaluate the geographical extent of each range. The Aravalli range is an ancient fold mountain system stretching from Delhi through Haryana and Rajasthan to Gujarat. Similarly, the Sahyadri (Western Ghats) acts as a continuous 1,600 km barrier along the western coast, traversing multiple states from Gujarat to Tamil Nadu. The Satpura range is a complex horst structure spanning across the heart of India through Gujarat, Maharashtra, Madhya Pradesh, and Chhattisgarh. By process of elimination, we find that the Ajanta range is the only one entirely confined within the borders of Maharashtra. As noted in INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.), the Ajanta hills are a part of the Deccan Plateau's internal structure, lacking the multi-state extension of its more prominent counterparts.

UPSC often uses common traps by listing famous ranges like the Sahyadri or Aravalli, which students study extensively but may forget to map against political boundaries. The trap here is scale; students often focus on the height or geological age rather than the specific territorial spread. Always remember: if a range is a major structural boundary of the Peninsular block, it is almost certainly multi-state. Localized internal ranges, such as Ajanta, are the exceptions you must look for when a question specifies only one State.