As the snow melts with the help of the warm sun and spring showers, the runoff in the high mountains makes its way to the brooks, streams, ponds, marshes and into a river. What is a river? It is nothing more than surface water that finds its way over land from higher altitudes to lower altitudes because of gravity and winds its way to an ocean or sea.

Most of the rivers form from the runoff originating in the mountains and surfaces along the river, but where the land dips below the water table, groundwater will enter flow.

Since little of Earth’s surface is perfectly flat, water flows down the slope of the land, forming small creeks, brooks, streams and rivers. As far as water science is concerned, rivers, streams, brooks and creeks are interchangeable terms used to define flowing water; however, people often use different terms to indicate the size of the flow, with creek being the smallest and river the largest (

Rivers, which vary in size, can carry tremendous amounts of water across the landscape. The three longest rivers in the world are the Nile at 4,160 miles, the Amazon at 4,000 miles and the Yangtze at 3,964 miles. ( In the United States, there are 13 large rivers that are more than 1,000 miles long. Six of the best-known are the Missouri, the Mississippi, the Yukon, the St. Lawrence, the Arkansas and the Colorado rivers. Length does not necessarily correlate with size. The Mississippi, though the fourth-longest river in North America at 2,350 miles, is the largest in volume, dumping 620,000 cubic feet of water per second into the Gulf of Mexico (

Rivers are important for life on Earth, not only for the numerous plants and animals that make their homes in and along rivers, but also for humans, who have relied heavily on rivers throughout history. For thousands of years, major civilizations have been built along riverbanks for access to fresh water and transportation. The Babylonian Empire developed at the fork of the Tigris and Euphrates rivers, the ancient Egyptian civilization developed along the Nile and the Roman Empire along the Tiber. Many major cities around the globe have been built along riverbanks, such as the Seine through Paris, the Thames through London, and the Yangtze through Shanghai. The capital of the United States is on the Potomac River.

In Maine, 30,000 miles of rivers and streams flow across the glacier-shaped landscape ( The St. John, St. Croix, Penobscot, Kennebec, Androscoggin, Presumpscot, Saco and Piscataquis rivers are the dominant rivers in Maine. These abundant waterways have played major roles in Maine’s cultural history, beginning with the earliest Wabanaki peoples, who include the Penobscot, Passamaquoddy, Maliseet and Micmac tribes. Rivers were their highways; the birch bark canoe is now a symbol of their ingenuity to use natural resources for transportation and other needs.

Rivers have played various roles in the history of European settlement since the 1600s. They were first a means to gain access to the land, and later commerce routes to transport one of Maine’s abundant natural resources, timber, to mills and seaports. Trees, cut into logs, were transported down the rivers in the major log drives from the 1700s until the early 1970s. In recent times the logs were used for papermaking in the mills beside the rivers.

We use the rivers today not only for transportation, but also to divert the water for flood control, irrigation, power generation, municipal uses and waste disposal.

You might have heard the phrase “rivers of life,” which reminds us that water is essential not only to humans but also to plants and animals. A river is a complex system of integral parts: the source, mouth, wetlands, flood plains, tributaries and the main riverbed. Because of the diverse habitats along their pathways, rivers support a variety of life and serve as important corridors for wildlife movement.

Among the well-known wildlife in Maine that depend on the rivers are the fish, notably the alewife, bass, brook and brown trout, salmon and sturgeon. The return of alewives, Atlantic salmon, bald eagles, ospreys, loons, geese and ducks are harbingers of Maine’s spring. Other river animals and plants include bullfrogs, coyotes, crayfish, egrets, herons, milkweed, monarch butterflies, wood ducks, moose, muskrats, owls and red foxes, to name just a few.

Rivers also provide ample opportunities for recreation. To help keep this important function of rivers in the forefront, the American Rivers organization has developed a plan for what they call Blue Trails, stretches of river that have safeguards to keep the water clean.


As you watch the snow piles dwindle, take a drive to your nearest river and observe the water, animal and plant life that abound. Whether it is the high water resulting from snowmelt, or the call of nesting eagles, rivers and their diverse surroundings are reminders that spring has arrived.

Joanne DeFilipp Alex is Northern Maine Geography Awareness coordinator for the National Geographic Society, with support from the Maine Geographic Alliance.

Sources & Resources:

Project WET:

Use the news:

Find articles related to rivers. What is the main topic of the articles? Locate the rivers on a map.

Geography challenge:

  1. Locate the rivers and the places mentioned in the article on a map.
  2. Find the definitions for the parts of the river: the source, mouth, wetlands, flood plains, tributaries and main riverbed. To what part of a river are you living closest?
  3. Locate the Amazon River and draw a line around its watershed. What countries are in its watershed?  (Answer: Peru, Brazil and Colombia.)
  4. Locate the six largest rivers in Maine and draw a line around their watersheds. Which river system is the largest? Which watersheds are located entirely in our state?
  5. The Mississippi River watershed includes 13 states. What are they?
  6. Maine has one river that has been designated as a National Wild and Scenic River. What river is it? Locate it on a map of Maine. (Answer: The Allagash.)
  7. What river winds 1,470 miles from the Rocky Mountains to the Gulf of California’s Sea of Cortez? (Answer:  Colorado River.)
  8. Johann Strauss II ‘s  “The Blue Danube Waltz” shares its name with a river on what continent? Which 10 countries does it flow through? (Answer:  Europe — Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Moldova, Ukraine and Romania.)
  9. Locate major cities on each continent. Are these cities located near a river? If so, which one? Now locate the river nearest to your home. What is it?

Where’s Monty?

Monty decided to explore a new country for him and visit one of its famous rivers. The river starts in an ice cave on the southern slopes of the Himalayas, approximately 10,300 feet above sea level and flows eastward, finally emptying into the Bay of Bengal. The mouth of the river is a vast delta. What country is Monty in and what river is he exploring? (Answer: India, the Ganges River.)