Detail from CC Pierce's 1908 panorama of Eagle Rock Valley. (ERVHS)
The combined flow of Eagle Rock's underground streams during the dry season enters the Los Angeles River through the two culverts on the left. (Googlemaps)
Stormdrains under Eagle Rock Boulevard near Fair Park Avenue. (Bureau of Engineering)


In the 1880s, several small tributaries emerged aboveground near the intersection of York and Eagle Rock Boulevards. These combined into a flow which followed a deep and meandering streambed before disappearing into the graveled banks of the Los Angeles River.

Cromwell Galpin describes how during this era, Eagle Rock Boulevard used to stop at the southern limit of Eagle Rock, making the journey to Los Angeles most vexing during the rainy season. The road would have stopped before reaching the low and swampy area from which the tributaries arose.

"... [H]e that went farther afoot, took his choice of a route across or around the hills, while he that drove a horse went where he could, across a morass if he turned to the right, and into the water if he went ahead; he that turned to the left went farther and fared worse, for he got into bottomless and almost boundless mud over in what is now a very pleasant part of the New York Valley..."

By the time of the USGS survey in 1894, the stream on Eagle Rock Boulevard was limited to seasonal flow, and its course had become simplified and relatively linear.

Streetcar tracks built on Eagle Rock Boulevard in the early 1900s were raised in several locations to accommodate water flow. An old timer describes the configuration of Eagle Rock Boulevard, as it approached the Los Angeles River:

"a two lane boulevard, with a small creek running down the middle of it. It was road, creek, trolley tracks. At the bottom of Avenue 31, there was a small wooden pedestrian bridge over the creek, between the road and the tracks. Moss Avenue had another bridge... About every two streets up the Boulevard had a bridge over the creek to reach the trolley..."