Mount Spencer is a 12,431 feet (3,789 m) peak in the Sierra Nevada, in Kings Canyon National Park and Fresno County, California.

It is named for Herbert Spencer, an English philosopher and prominent scientist in the field of evolution who coined the term "survival of the fittest."

[5] Most weather fronts originate in the Pacific Ocean, and travel east toward the Sierra Nevada mountains.

As fronts approach, they are forced upward by the peaks, causing them to drop their moisture in the form of rain or snowfall onto the range (orographic lift).

Precipitation runoff from this mountain drains to Evolution Creek which is a San Joaquin River tributary.