While rivers are typically known for their vast, winding courses, not all of them travel great distances. For instance, Montana's Roe River spans only 201 feet (61 meters), flowing between Giant Springs and the Missouri River.
The Roe River earned the title of the shortest river in the world in the 1989 Guinness Book of World Records. Prior to that, the title was held by the 440-foot-long (134 meters) D River in Lincoln City, Oregon. Both rivers have had their lengths measured multiple times, and residents from both towns soon began debating which river deserved the title. In 2006, Guinness decided to avoid the dispute and removed the category altogether.
The World Atlas mentions other even shorter rivers around the world, such as Indonesia's Tamborasi River, which measures just 20 meters (65.6 feet) long, and Norway's Kovasselva River, also measuring 65.6 feet in length.
Can a river really be just 65 feet long? The reality is that the definition of a river is quite expansive. As per the U.S. Geological Survey, a river is characterized by constantly flowing water, originating from upland sources, and eventually depositing water into the ocean, another river, a lake, or a watershed. In general, creeks and brooks combine to form streams, streams merge to become rivers, and rivers carry water from higher to lower elevations, ultimately emptying into the ocean.
In 1952, Columbia University geoscience professor Arthur Newell Strahler introduced a system for classifying streams and rivers. The Strahler Stream Order Classification organizes rivers into 12 orders, based on the number of tributaries they have. Tributaries are streams or rivers that don't directly flow into the ocean but instead feed a larger river or stream.
Streams ranked one or two are smaller and flow into larger streams without other tributaries feeding them. Headwater streams, which feed into the upper parts of a watershed, are classified from first to third order and account for over 80 percent of global waterways. Streams from fourth to sixth order are medium-sized and are fed by smaller streams, while those above the sixth order, fed by many tributaries, are classified as rivers.
The Mississippi River is an eighth order stream, while the Amazon River, the largest river in terms of water volume, is a 12th order stream. Stretching for 4,345 miles (6,993 kilometers), the Amazon makes Montana's Roe River look like a mere trickle in comparison.
The world's most polluted river is Indonesia's Citarum River. Once the heart of the Buni clay pottery-making civilization in ancient times, today the river is overwhelmed with plastic, household and industrial waste, raw sewage, and other human garbage, rendering the water nearly impossible to see.