The North Fork San Gabriel River is a tributary, 4.5 miles (7.2 km) long, of the West Fork San Gabriel River in the Angeles National Forest of Los Angeles County, California. The river originates at the confluence of Soldier Creek and Coldbrook Creek in the San Gabriel Mountains below the village of Falling Springs and flows down a steep canyon in a southerly direction to join the West Fork near San Gabriel Reservoir. The North Fork Canyon provides the route for SR 39, one of the main access roads to the Angeles Forest.

North Fork San Gabriel River
Location of the North Fork in California
Location
Country	United States
State	California
Physical characteristics
Source	Near Falling Springs
• location	Angeles National Forest, San Gabriel Mountains
• coordinates	34°17′27″N 117°50′25″W / 34.29083°N 117.84028°W / 34.29083; -117.84028[1]
• elevation	3,275 ft (998 m)
Mouth	West Fork San Gabriel River
• location	Near San Gabriel Reservoir
• coordinates	34°14′29″N 117°52′08″W / 34.24139°N 117.86889°W / 34.24139; -117.86889[1]
• elevation	1,552 ft (473 m)
Length	4.5 mi (7.2 km)[1]
Basin size	18.6 sq mi (48 km2)[2]
Discharge
• location	Camp Rincon, near the mouth[2]
• average	6.6 cu ft/s (0.19 m3/s)[2]
• minimum	1.16 cu ft/s (0.033 m3/s)
• maximum	276 cu ft/s (7.8 m3/s)

Crystal Lake, the only natural lake in the San Gabriel Mountains, is located above the headwaters of the North Fork in the Crystal Lake Recreation Area at an elevation of 5,600 feet (1,700 m). The area has campsites, trails and picnic areas and is one of the more popular sites in the Angeles National Forest.^[3][4]