Aravalli Hills: Why is 2-billion year old mountain range is in news and the reason it is most crucial for North India

Did you know that India is home to seven major mountain ranges? They are the Himalayas, the Aravalli, Vindhya, Satpura, Western Ghats, Eastern Ghats, and the Purvanchal. And of all these seven, the Aravallis is the oldest, estimated to be around 2 billion years old. But that’s not all, the Aravalli Range is not only the oldest mountain range in India but also among the oldest geological formations on Earth. Also interesting, The Aravalli Range was formed during the Proterozoic era, long before the dinosaurs appeared, and a long ago before the Himalayas. This was the period when first stable continents were formed. The Aravallis is that old. Today, the Aravallis stretch across Gujarat, Rajasthan, Haryana, and Delhi, this ancient range continues to fascinate history and nature enthusiasts.
But why is the Aravalli Range in the news right now? The Aravalli Range is in the news following a recent Supreme Court-backed move to adopt a new, uniform definition of the Aravalli hills. This new, uniform definition of the Aravalli Hills and Ranges that was accepted by the Supreme Court of India in late 2025, following recommendations made by a committee under the Ministry of Environment, Forests and Climate Change, states that a hill will be recognised as an “Aravalli Hill” only if it rises at least 100 metres above the surrounding land, and a stretch will count as an “Aravalli Range” only when two or more such hills lie within 500 metres of each other.
Now, what does this mean? The new definition classifies them based on specific height and geological criteria. But looking at the geographical features of the mountain range, this redefinition could exclude large stretches of the ancient mountain system, especially lower hillocks and forested ridges, from legal protection. What does this mean, you ask? So this potentially makes these areas vulnerable to mining and real estate development. As expected, this has triggered widespread protests and online campaigns such as “Save Aravalli”, particularly in Rajasthan, Haryana, and the Delhi-NCR region. The central government, however, has pushed back against these concerns, maintaining that over 90 per cent of the Aravalli region remains protected and that no relaxation of mining norms has been allowed. The debate has brought renewed national attention to the ecological importance of the 2-billion-year-old Aravalli Range, especially its role in preventing desertification, supporting groundwater recharge, and sustaining wildlife corridors.

Did you know that the Aravallis also act as a natural barrier against the spread of the Thar Desert? And not only that, the mountain range is also a crucial wildlife corridor.
Below are some of the most important and visitor-friendly places within this 2-billion-year-old mountain system, showcasing why the Aravallis remain ecologically and culturally relevant even today.

Sariska Tiger Reserve lies firmly within the Aravalli Range and is shaped by its ancient geology. Today, Sariska is a safe home to tigers, leopards, striped hyenas, jackals, sambar deer, and a rich variety of birds. It was not too long ago that Sariska, being a tiger reserve, had no tigers. But due to successful conservation programmes, today, the big cat population is not only increasing, but thriving too. Jeep safaris here offer a chance to experience wildlife against the backdrop of 2-billion-year-old hills.

Rajasthan’s only hill station, Mount Abu is the highest peak of the Aravalli Range and a striking exception to Rajasthan’s arid image. It’s cooler here, and the vegetation is more diverse. The Mount Abu Wildlife Sanctuary is also home to leopards, jungle cats, sambars, and several rare plant species.

Did you know that Jhalana Leopard Safari Park is located within Jaipur city limits? Jhalana demonstrates how wildlife can coexist with urban environments. Jhalana is best known for its leopard population, along with desert foxes, striped hyenas, and several species of birds of prey. Safari drives here are among the most accessible ways to experience the Aravallis’ wildlife without venturing far from a major city. Want to see a leopard? This is one of the best places to do so.

History and wilderness blend seamlessly here. Encircling the iconic Kumbhalgarh Fort, the sanctuary protects a vast, largely untouched stretch of the Aravalli Range. Characterised by steep escarpments, thick forest cover and secluded valleys, this rugged landscape has been moulded by geological forces dating back nearly two billion years. The reserve also supports a thriving wildlife population, including leopards, wolves and sloth bears, along with herbivores such as chital and nilgai.

The Delhi Ridge is the northernmost extension of the Aravalli Range, making it one of the world’s oldest mountain systems to exist within a modern megacity. The ridge plays a vital role in maintaining Delhi’s ecological balance, and forms one of the most important green pockets in the city. Here you will find wildlife like nilgai, jackals, porcupines, reptiles, and numerous bird species.

A large part of the Aravallis stayed degraded for long, till restored biodiversity parks in Gurugram and Delhi revived those sections. By introducing native grasslands, scrub forests, and wetlands, today, these parks have become prominent attractions for wildlife enthusiasts. Find migratory birds, butterflies, reptiles, and small mammals.

One of the Aravallis’ most crucial roles is acting as a natural ecological barrier between fertile plains and the Thar Desert. For over 2 billion years, these hills have influenced wind patterns, rainfall distribution, and soil retention across western India. The scrub forests and grasslands along the desert edge support species such as wolves, desert cats, foxes, and migratory birds.