Although the region gradually rises to the west, it appears mostly level.
Precipitation decreases from east to west.
Trees are found only along watercourses. Covered by grasses whose height varies with the amount of rainfall received, the soil of the pampas is very fertile and supports a thriving pastoral and farming economy. Cattle was first introduced to the region by the Portuguese in the 1550s. Herds of cattle roamed freely over the Pampa, and the gaucho , the Argentine cowboy, was the region's dominant figure in the 18th and early 19th cent. A new economic era was initiated in the second half of the 19th cent.