Is 2,500 km (1,554 miles) long--the approximate distance from New York, New York to Denver, Colorado--and averages 72 km (45 miles) wide. The deep, colossal trench is unaffected by human activity because it is inaccessible to most humans and things like overfishing, global warming and pollution do not affect these extreme depths. We do not know of any endangered species, both because human activity has not threatened any creatures and little is known of the many deep-sea species. Only three men have ever descended all the way to the bottom of the ocean, and very few have scratched the surface of Mariana's depths. However, the trench serves as a major expressway for submarines in the Pacific Ocean wishing to stay undetected in deeper waters.