Houston–Sugar Land–Baytown is a 10-county metropolitan area defined by the Office of Management and Budget. It is located along the Gulf Coast region in the U.S. state of Texas. The metropolitan area is colloquially referred to as "Greater Houston" and is situated in nowrap: East Texas, west of the Golden Triangle.

Houston–Sugar Land–Baytown is the sixth-largest metropolitan area in the United States with a population of 5.6 million as of the 2007 U.S. Census estimate.U.S. Census Bureau, 2000 to 2007 Population Estimates The population of the metropolitan area is centered in the city of Houston—the largest economic and cultural center of Texas with a population of 2.14 million.

Houston is among the nation's fastest-growing metropolitan areas. The area grew 25.2 percent between the 1990 and 2000 censuses—adding more than 950,000 people—while the nation's population increased 13.2 percent over the same period. From 2000-2007, the area grew by 912,994 people.

From 2000 to 2030, the metropolitan area is projected by Woods & Poole Economics to rank fifth in the nation in population growth—adding 2.66 million people.

Geography

The metropolitan area is located in the gulf coastal plains biome, and its vegetation is classified as temperate grassland. Much of the metro area was built on forested land, marshes, swamp, or prairie—all of which can still be seen in surrounding areas. The further north you go in the Houston metro, you can find scenic rolling hills. Most notably, in Conroe, Magnolia, and Willis.

Much of the Houston metropolitan area is very flat, making flooding a recurring problem for some areas.

Geology

Underpinning Houston's land surface are unconsolidated clays, clay shales, and poorly-cemented sands up to several miles deep. The region's geology developed from stream deposits formed from the erosion of the Rocky Mountains. These sediments consist of a series of sands and clays deposited on decaying organic matter that, over time, transformed into oil and natural gas. Beneath these tiers is a water-deposited layer of halite, a rock salt. The porous layers were compressed over time and forced upward. As it pushed upward, the salt dragged surrounding sediments into dome shapes, often trapping oil and gas that seeped from the surrounding porous sands. This thick rich soil also provides a good environment for rice farming in suburban outskirts that the city continues to grow into near Katy. Evidence of past rice farming is even still evident in developed areas as there is an abundance of rich dark loamy top soil.

The Houston region is generally earthquake-free. While the city of Houston contains over 150 active surface faults (some have estimated as many as 300 active faults) with an aggregate length of up to 310 miles (500 km), the clay below the surface precludes the buildup of friction that produces ground shaking in earthquakes. These faults generally move at a smooth rate in what is termed "fault creep."