Otters are among the most adaptable mammals alive, thriving everywhere from icy coasts to steamy rainforests. This list reveals the eight largest species, from the massive giant otter of South America ...

Rivers have served as lifelines for civilizations throughout history, shaping landscapes and cultures across continents. These mighty waterways continue to fascinate researchers and explorers today, ...

Groundwater sustains the Rio Grande and its wildlife, but overuse and pollution threaten this vital freshwater source. Learn how it can be restored.

Bill Vaughn is right. Mathematically, it is possible for a single game to last forever. Some might argue that a few certainly feel like they have. Baseball's extra-innings rule in the regular season — ...