evidence: The stakes are high for Guyana. Venezuela claims all the territory west of the Essequibo River, which begins near the border with Brazil and runs 600 miles north to the Atlantic Ocean, making it South America’s third-largest river after the Amazon and the Orinoco. Not surprisingly, the derivation of the river’s name is itself disputed. One account is that the name derives from an Arawak word meaning "hearth-stones," said to be a reference to the Arawak custom of collecting stones from the river’s banks for their firesides. Another explanation associates derivation with explorer Juan de Esquivel, who reputedly traveled into the Essequibo area beginning in the 16th century along the river that later was dubbed Esquivel's River. The Essequibo region, which Venezuela calls the zona en reclamación ("reclamation zone"), comprises 61,600 square miles of Guyana’s 83,000 sq mi, almost 75 percent of the country or about the size of the state of Massachusetts and a little more than the state of Georgia. It could accommodate all of England with room to spare, Jamaica fourteen-and-a-half times, and Costa Rica three times. The territory spans 6 of Guyana’s 10 administrative regions and contains around 300,000 of the country’s estimated population of just under 800,000. Many of these residents—as much as 89 percent of the population in the Upper Essequibo region—are members of Guyana’s nine distinct Indigenous groups: the Lokono (Arawak), Akawaio (Kapon), Arecuna (Pemon), Macusi, Warrau, Wapisiana, Wai, Patamona, and Kalina (Carib).