As more steams converge the water the stream then becomes a full fledged river. When the river crosses bedrock layers larger waterfalls are formed. Pollution becomes more apparent. 2000 feet above water. From here the river leaves the mountains and becomes very flat and dirty from increased soil runoff. Farms and big cities dot the landscape adding more pollution. The river makes large meanders in flat open land until it joins other rivers and eventually meets the oceans.