FREE USA Mountains and Rivers Quiz: 20 Questions with Answers

Explanation: Mount St. Helens erupted violently in 1980, blowing 1,300 feet off its top and killing 57 people. Located in the Cascade Range, it's still active and monitored closely by scientists for future eruptions.

Explanation: The Tennessee River flows 652 miles through seven states, powering the Tennessee Valley Authority (TVA) dams. Nashville's music scene sits on its tributary, the Cumberland.

Explanation: Lake Superior covers 31,700 square miles between the U.S. and Canada. 10% salt would make the Great Lakes saltier than all the world's oceans combined. Famous for shipwrecks and the Edmund Fitzgerald song.

Explanation: The Alaska Range runs 400 miles across south-central Alaska. Denali's extreme height comes from rising directly from near sea level rather than a high plateau.

Explanation: The Sierra Nevada runs 400 miles through eastern California, peaking at Mount Whitney (14,505 feet). Home to Yosemite and Sequoia National Parks, plus the Donner Party tragedy site and the California Gold Rush.

Explanation: "Old Man River" flows 2,340 miles from Minnesota to the Gulf of Louisiana, passing through or bordering 10 states. Mark Twain called it "the Father of Waters." It's the largest river system in North America.

Explanation: Over 6 million years, the Colorado River cut through Arizona's rock layers, creating the 277-mile-long, 1-mile-deep Grand Canyon. The river still flows through seven states, supplying water to 40 million people and generating hydroelectric power.

Explanation: The Mississippi River and 2 million tributaries drain 1.2 million square miles across 31 states and 2 Canadian provinces—the largest watershed in North America.

Explanation: Denali in Alaska stands 20,310 feet tall, making it North America's highest peak. Located in Denali National Park, it's taller than any mountain east of the Mississippi by over 10,000 feet. Climbing Denali is extremely challenging—only about half of climbers reach the summit due to brutal weather and altitude.

Explanation: Mount Rainier (14,411 feet) looms over Seattle in Washington. Covered in 26 glaciers, it's considered one of the most dangerous volcanoes due to potential lahars (mudflows) threatening nearby cities.

Explanation: The Rio Grande flows 1,896 miles from Colorado to the Gulf of Mexico, forming 1,255 miles of the U.S.-Mexico border. Called Río Bravo del Norte in Mexico, it provides water for agriculture in Texas and New Mexico.

Explanation: Kilauea on Hawaii's Big Island has erupted continuously since 1983, adding 500 acres of new land. It's in Hawai'i Volcanoes National Park and sacred to native Hawaiians as the home of Pele, goddess of fire.

Explanation: The Niagara River flows from Lake Erie to Lake Ontario, plunging 167 feet at Niagara Falls. 3,160 tons of water fall every minute, generating hydroelectric power for both the U.S. and Canada.

Explanation: The Rockies span 3,000 miles from Canada to New Mexico, averaging 10,000 feet high. Known as the "Spine of America," they divide watersheds flowing east to the Atlantic and west to the Pacific. Home to 78 major peaks over 14,000 feet.

Explanation: The Merrimack River's water-powered mills in Massachusetts and New Hampshire launched America's textile industry in the 1800s. Today it flows through six New England states to the Atlantic Ocean.

Explanation: Daniel Boone blazed the Cumberland Gap trail through the Appalachians to the Ohio River Valley, opening Kentucky and Tennessee for settlement in the late 1700s.

Explanation: The Appalachians stretch 1,500 miles from Alabama to Newfoundland, Canada. Formed 480 million years ago, they're the oldest mountains in the U.S. Famous for the Blue Ridge Parkway, Shenandoah National Park, and the Appalachian Trail (2,190 miles long).

Explanation: The Missouri River stretches 2,341 miles from Montana through seven states to meet the Mississippi near St. Louis, Missouri. Though the Mississippi is more famous, the Missouri is longer by over 200 miles. Lewis and Clark followed it during their 1804 expedition to explore the West.

Explanation: The Panamint Range rises 11,000 feet above Death Valley (282 feet below sea level). Telescope Peak offers stunning views of the lowest and highest points in the contiguous U.S. from one spot.

Explanation: Colorado's Rocky Mountains contain numerous passes crossing the Continental Divide, where rivers flow either east to the Atlantic or west to the Pacific Ocean.