It's about one-and-a-half times as long as The Grand Canyon.
In other words, 681.9 kilometers is 1.53 times the length of The Grand Canyon, and the length of The Grand Canyon is 0.654 times that amount.(a.k.a. Gran Cañón) (Arizona) (Colorado River miles measure)
It's about half as long as The Rhine.
In other words, 681.9 kilometers is 0.517 times the length of The Rhine, and the length of The Rhine is 1.93 times that amount.(a.k.a. Rhein, a.k.a. Rijn, a.k.a. Rhin, a.k.a. Rain, a.k.a. Reno, a.k.a. Rhenus, a.k.a. Ryn) (from near Reichenau, Switzerland through Hoek van Holland, Rotterdam, Netherlands)
It's about three-tenths as long as The Colorado River.
In other words, 681.9 kilometers is 0.293 times the length of The Colorado River, and the length of The Colorado River is 3.41 times that amount.(a.k.a. Aha Kwahwat, a.k.a. Grand River, a.k.a. Tizon River, a.k.a. Tecon River, a.k.a. Tison River) (from Grand Lake, Colorado through the Gulf of California)
It's about one-fourth as long as The Danube.
In other words, 681.9 kilometers is 0.239 times the length of The Danube, and the length of The Danube is 4.18 times that amount.(a.k.a. Donau, a.k.a. Dunaj, a.k.a. Dunav, a.k.a. Duna, a.k.a. Дунав (Dunav), a.k.a. Dunărea, a.k.a. Дунáй (Dunay), a.k.a. Tuna) (from Breg Martinskapelle, Black Forest, Germany through the Danube Delta, Romania)
It's about one-fifth as long as The Oregon Trail.
In other words, 681.9 kilometers is 0.195 times the length of The Oregon Trail, and the length of The Oregon Trail is 5.13 times that amount.(from Independence, Missouri to Oregon City, Oregon)
The historic Oregon Trail stretched 3,490 km across five (sometimes six) states in the western United States. In the early years of the Trail's existence, the trip was estimated to have taken an average of 160 days.
It's about one-fifth as long as The Volga.
In other words, 681.9 kilometers is 0.193 times the length of The Volga, and the length of The Volga is 5.18 times that amount.(a.k.a. Волга, a.k.a. İdel (Идел), a.k.a. Атăл (Atăl), a.k.a. Edil, a.k.a. İdil, a.k.a. Рав (Rav)) (from the Valdai Hills, Tver Oblast, Russia through the Caspian Sea)
It's about one-fifth as long as The Mississippi River.
In other words, 681.9 kilometers is 0.1811 times the length of The Mississippi River, and the length of The Mississippi River is 5.522 times that amount.(from Lake Itasca, Minnesota through Pilottown, Plaquemines Parish, Louisiana)
The total length of the Mississippi River is 3,766 km. Prior to the development of soil erosion programs, the Mississippi River would carry approximately 400 million metric tons of sediment from its banks to the Gulf of Mexico every year.