Final answer:
The tropical grassland region east of the Andes in Colombia and Venezuela is known as the Llanos. This large and remote area is primarily used for cattle ranching due to its expansive grasslands and is characterized by a small human population.
Step-by-step explanation:
The region of Colombia and Venezuela which is a tropical grassland located east of the Andes is known as the Llanos. This extensive area consists of large grassland plains that stretch from the Colombian border down to the Orinoco River delta. The Llanos region, notable for its sparsely populated expanses, is primarily utilized for cattle raising due to its flat terrain and propensity for seasonal flooding.
In Venezuela, the northern coastal regions are dominated by the Andes Mountains, but as one moves south from the Colombian border, the topography transitions into the vast grasslands of the Llanos, which occupy around one-third of the country. The remoteness of the Llanos and the challenges it presents, such as flooding, have resulted in a small human population and a reliance on cattle ranching as the main economic activity.
This region is synonymous with the tropical grasslands east of the Andes that extend into Venezuela and Colombia, acting as a stark contrast to the dense rainforests and rugged Guiana Highlands that lie to the east and southeast.