by Sam Dolinar
The JPL-Smith Bridge-Devil's Gate Dam 10K Course was once an officially measured 10K course consisting of a loop around Devil's Gate Dam from JPL of just over 3 miles, plus an out-and-back section of just under 3 miles up Arroyo Seco Canyon to the stream crossing just beyond the Elmer Smith Bridge. It was decertified as an official 10K course when the old bridge over Flint Canyon (just to the west of Devil's Gate Dam) was condemned and later razed. After the new Flint Canyon Bridge was opened in 2007, this route is again passable at its southern limit, but now there's a circumventable bridge outage near its northern turnaround point on the Arroyo Seco Canyon Road.
Here's a map from the 1980s describing the JPL-Smith Bridge-Devil's Gate Dam 10K Course.