[6][7] The first European land exploration of Alta California, the Spanish Portolá expedition, traversed Whittier Narrows on its return journey to San Diego.

We traveled a long while to the southwest on the edge of the stream, which, rising from a copious spring of water in the same gap, merits now the name of river; its plain is covered with willows and some slender cotton woods."

On October 1, 1987 at 7:42 a.m. PDT, the 5.9 Mw  Whittier Narrows earthquake affected the Greater Los Angeles Area with a maximum Mercalli intensity of VIII (Severe).

[11] The Whittier Narrows Dam is a flood control and water conservation project constructed and operated by the U.S. Army Corps of Engineers, Los Angeles District.

It collects runoff from the uncontrolled drainage areas upstream along with releases from the Santa Fe Dam, and can redirect flows into the Rio Hondo or the downstream San Gabriel.