Back in 20th century; when extensive excavations first begun & evidences of two large settlements were found, Harappa & Mohenjo-Daro (later Rupar & Lothal) archeologists never had the glut of resources & information as we posses today.
2. However, in this age of excesses it becomes even more pertinent that we handle information with utmost care & a sense of responsibility. Exaggerations, jingoistic interpretations & over the top non senses do more harm than good. Therefore, I’ll try construct the boundaries of IVC (Indus Valley Civilization) treading the middle path employing archeological evidences that are widely accepted.
3. Excavation sites extend from: Harappa (Punjab) to ports of Dholavira & Surkotada (Gujarat). Evidences of settlements also exist in Baluchistan & parts of Gangetic plains in east (Doab).
This surely gives us a rough idea of the extent of IVC as below (covering large parts of modern Pakistan & Indian states of Punjab, Gujarat & vestiges of Rajasthan):
4. Extensive trade links with contemporary cultures of Mesopotamia & Nile Valley do provide us with compelling indications of movement of men & goods either ways. People of IVC were the first to use bullock carts (or any wheeled transportation) & this surely help intensify trade & commerce. There are vital evidences to ascertain the widely believed notion of IVC being involved in maritime trade. IVC had trade links with settlements in modern state of Oman. I firmly espouse the view that there were trade outposts in region of Oman owing to the fact that technologies in antiquity could never support marine movements against the flow of wind (remember: sailing was yet to be discovered). Hence, merchants were forced to wait for next season which could facilitate shipping. Similar outposts could also be found in parts of Central Asia. However, these trade outposts were mostly temporary & transitory & hence, can never be taken as extensions of IVC.
5. One important fact worth underlining is: IVC prospered in an age of glut of water- resources (Last ice age ended in 10,000BC & hence, there were many gigantic glaciers in Upper Himalayas). Baluchistan & Sindh in those days were fertile plains thick with vegetation. Most of the Gangetic plain was a swampy land & hence, inhospitable.