Houston's Size
The Houston City Statistical Area (CSA) covers 12,476 square miles, an area larger than Maryland (12,297 square miles).
The Houston Metropolitan Statistical Area (MSA) covers 10,062 square miles, an area slightly smaller than Maryland but larger than Massachusetts (9,241 square miles).
Harris County covers 1,778 square miles, an area nearly half again as large as Rhode Island (1,231 square miles).
At 634 square miles, the City of Houston could contain the cities of New York, Washington, Boston, San Francisco, Seattle, Minneapolis and Miami.
The Houston MSA contains more people than Minnesota, which ranks 21st among the states in population.
Harris County contains more people than Oregon, which ranks 27th.
Green Houston 
