In the Tárcoles River in Costa Rica there are dozens of 4-meter and a few 5-meter individuals that frequent bridge crossings (where they are fed daily, which may have helped them reach such consistently large sizes) and are a popular tourist attraction. In the United States adult length has been recorded as high as 4.9 metres (16 ft). This species is said to grow largest in the South American river basins, but even old males rarely reach 6 metres (20 ft). A skull of this species was found to measure 72.6 centimetres (28.6 in) and is estimated to have belonged to a crocodile of 6.6 metres (22 ft) in length. Large, mature males regularly weigh about 400-500 kg (880-1100 lb), with the 6 meter+ individuals surpassing 1000 kg (2,200 lb). The longest American crocodile ever actually measured from snout to tail is a 17 feet (5.2 m) male living within the Tarcoles River of Costa Rica.