| Arroyo Seco Freako Microthon: Courses over the Years | |||||
| Race Year(s) | Course Length | Start Location | Finish Location | Wash Crossings | |
| West-to-East | East-to-West | ||||
| 1975 | 2.5 mi | UHP/LHP ? | LHP ? | DGD via UHP | Trail crossing |
| 1976 | 3.8 mi | UHP Rd Jcn | LHP Fire Camp | DGD via UHP | Trail crossing |
| 1977 | 3.5 mi | UHP Rd Jcn | LHP Picnic | DGD via UHP | Trail crossing |
| 1978-1982 | 4.2 mi | UHP Rd Jcn | UHP Rd Jcn | DGD via UHP | DGD via UHP |
| 1983 | 5K + 200 ft | Rd ^ East Lot | Rd ^ East Lot | none | none |
| 1984 planned | 4.3 mi | LHP Picnic | LHP Picnic | Trail crossing | Trail crossing |
| 1984-1997 | 5K | LHP Carpark | LHP Picnic | none | none |
| 1998-2007 | ~3.45 mi | LHP Carpark | LHP Picnic | DGD via OGD | E-Gate Br |
| 2008-2012 | 3.33 mi | LHP Carpark | LHP Picnic | DGD via UHP | E-Gate Br |
| 2013 | 3.24 mi | LHP Carpark | LHP Picnic | DGD via UHP | Trail crossing |
| Key to Start/Finish Locations | |||||
| UHP - Upper Hahamongna Park (formerly Upper Oak Grove Park) | |||||
| LHP - Lower Hahamongna Park (formerly Lower Oak Grove Park) | |||||
| UHP Rd Jcn = junction of UHP road with UHP-to-LHP road | |||||
| LHP Fire Camp - LA County Fire Suppression Camp in LHP | |||||
| LHP Picnic = picnic area south of LHP baseball field | |||||
| LHP Carpark = parking lot east of LHP baseball field | |||||
| Rd ^ East Lot = Forest Service road above JPL's East Parking Lot | |||||
| Key to Crossings of Arroyo Seco Wash | |||||
| DGD via UHP = roadway atop Devil's Gate Dam via UHP bridge across Flint Cyn | |||||
| DGD via OGD = roadway atop Devil's Gate Dam via Oak Grove Dr across Flint Cyn | |||||
| Trail crossing = Trail across wash to/from JPL South corner fence | |||||
| E-Gate Br = Bridge across wash at JPL's East Gate | |||||
| "none/none" means that course stayed entirely on Start/Finish side of wash | |||||