The southernmost river in the Sierra Nevada, the Kern River is also distinguished by being the only one in this range which flows from north to south much of its distance, draining much of the southernmost portion of the range. The North Fork starts near Mt Whitney and travels south quite a long distance before joining the smaller South Fork in Lake Isabella. After this point it roars through a treacherous canyon before pouring into the San Joaquin Valley. At one time it terminated here in a huge swampy lake, but sadly, this lake is now gone (except during floods) and the water is now used to irrigate crops.

The northern portion of this river, Upper Kern Canyon, is some of the remotest and wildest country in the United States(outside of Alaska) - the nearest road is a three day hike away. The southern portion of the river has been tamed by dams and hydroelectric power generators. Although it is much diminished, it is still a powerful river. Many people have died swimming in the waters of the united Kern below Lake Isabella despite the warning signs. The river looks peaceful but the undercurrents are fierce. Some brave individuals raft down this portion of the river, but most just look on from the nearby highway.