elevation above which it is too cold for trees to grow
seasonal warm wind that blows down the rockies in late winter and early spring
an inland grassland area
violent thunderstorms that can spawn tornadoes
a large, powerful windstorm that forms over warm ocean waters
a snow storm with winds of more than 35 miles per hour, temperatures below freezing, and visibility of less than 500 feet for 3 hours or more.
the movement of people from one country into another.
North America's first immigrant, who probably moved into the region from Asia thousands of years ago.
mild climate region, souther united states.
the movement if people from rural areas into cities.
region that includes a central city and its surrounding suburbs.
outlying community around a city.
a "super city" that is made up of several large and small cities such as the area between boston and washington
able to move from place to place
form of government without a monarch in which people elect their officials
an informal network of safe houses, in the united states, that helped thousands of enslaved people escape to freedom.
farming method used in dry regions in which land is plowed and planted deeply to hold water in the soil.
plan of government made for the united states in 1787
in U.S history, official changes made to the constitution
Bill of Rights
the first 10 amendments to the united states constitution
heads of departments in the U.S government who advise the president.