Top 10 geography of the United States facts Selected as the most interesting among North America related questions in North America quiz Why is White Sands Desert in New Mexico so purely white?It is gypsum. White Sands, having 442 total square kilometers of dune fields, is the world's largest surface deposit of gypsum. Unlike other desert sands, it is cool to the touch, due to the high rate of evaporation of surface moisture and the fact that the sands reflect, rather than absorb, the sun's rays.Created by: Debbie Foxnatural resources facts » What is the longest river in the United States?Missouri. The Missouri River is the longest river in North America. Having 2,341 mi (3,768 km), it is longer than the Mississippi (2,202 mi 3,544 km). When combined with the lower Mississippi River, it forms the world's third longest river system, after the Nile and Amazon.Created by: Shankar Kumarrivers of North America facts » What is Santa Clara Valley better known as?Silicon Valley. The term Silicon Valley first appeared in the Electronic News newspaper in 1971. In 2006, Silicon Valley had 225,300 high-tech jobs.Created by: KasiaCalifornia facts » What is the third longest river of the North America? (after Mississippi and Missouri)Yukon, having 1,979 mi (3,185 km), is just 223 miles shorter than Mississippi. Despite its length, there are only four vehicles-carrying bridges across the river.Created by: globalquiz.orgAlaska facts » Which river flows through the Grand Canyon?Colorado River established its course through the canyon at least 17 million years ago. Since then, it exposed about two billion years of the Earth's geological history.Created by: globalquiz.orggeography of North America facts » What is the second most populous state in the USA? (after California)Texas. The 4 most populous states are California (38M), Texas (26M), New York (19M) and Florida (19M).Created by: globalquiz.orgNorth America facts » Which state of the USA is that?Washington. Such large and rocky mountains are found only on the west of the North America. This is a photo of Mount Rainier over Tacoma, Washington, USA.Created by: globalquiz.orgmountains facts » Where is New York?At point 1. The easily recognizable Long Island extends 118 miles (190 km) eastward from New York Harbor. It is both the longest and the largest island in the contiguous United States. Created by: globalquiz.orgcities of North America facts » Where is Niagara Falls?At point 3. Located on the Niagara River, which drains Lake Erie into Lake Ontario, the combined falls form the highest flow rate of any waterfall in the world.Created by: globalquiz.orgwaterfalls facts » Where is the capital of the United States?At point 2. The states of Maryland and Virginia each donated land to form the federal district with Washington.Created by: globalquiz.orgmaps facts » Play North America quiz and see all the questions.