Early Planning and Purpose (1900s–1920s)

The idea for the Angeles Crest Highway emerged in the early 20th century as Los Angeles expanded. Local boosters envisioned a road to open the San Gabriel Mountains for motorists and provide better access for fire control. In 1919, survey work began, led by engineer J.B. Lippincott. The proposed route followed high ridges with a maximum grade of about 6.5% and broad, sweeping curves. It was intended to provide city residents with access to alpine scenery while enabling fire crews to reach remote areas.

Construction of the Highway (1929–1956)

Construction began in 1929 under the California Division of Highways with the U.S. Bureau of Public Roads. Work stretched across 27 years, interrupted only by World War II. Laborers included unemployed men, Civilian Conservation Corps teams, and prison inmates from San Quentin and Chino. Crews blasted through granite, carved cuts up to 240 feet deep, and built bridges across gullies. Near Islip Saddle, two tunnels were excavated to carry the road through high ridges. The road reaches its highest point at Dawson Saddle (7,901 feet).

By 1932, the first segment opened from La Cañada Flintridge to Red Box Saddle, drawing millions of visitors in a short time. This shift in access transformed mountain recreation from hiking to automobile tourism. After decades of incremental progress, the final segment to Big Pines and Wrightwood opened in 1956, completing the 66-mile route.

Mid-Century Developments and Scenic Recognition (1957–1970s)

Once completed, the road quickly became popular but faced constant threats from landslides and erosion. In 1971, the Angeles Crest Highway was designated a California State Scenic Highway, covering 55 miles from La Cañada to the county line. Though briefly included in the state freeway plan in 1959, it was removed in 1978.

That same year, a massive landslide destroyed the connection between State Route 2 and State Route 39 near Islip Saddle. The damage was never repaired, ending the dream of a continuous scenic loop through the San Gabriels.

Scenic Byway Designation and Ongoing Challenges (1980s–2000s)

In 1990, the federal government designated the route a National Forest Scenic Byway, recognizing its national importance. By then, the highway had become both a popular drive and a hotspot for motorcycle accidents, prompting safety crackdowns.

Wildfires and storms caused repeated damage. The 2009 Station Fire burned vast stretches of forest, followed by heavy rains in 2010 that washed away road sections. The road remained closed for nearly two years, reopening in June 2011 after major repairs.

Recent Events and Repairs (2010s–2025)

Caltrans has continued upgrades, including resurfacing and safety improvements. Yet the cycle of damage and repair persists—the Bobcat Fire in 2020 and the Bridge Fire in 2024 forced closures. Severe storms in 2022–23 caused major washouts between Islip Saddle and Vincent Gulch, requiring a multi-year, multimillion-dollar rebuild.

In August 2025, Caltrans reopened the full highway after more than two years of partial closure. Travelers can once again drive from La Cañada to Wrightwood, though closures remain an ongoing reality in this unstable mountain environment.

Cultural and Scenic Importance

The Angeles Crest Highway transformed recreation in Los Angeles, bringing millions into the mountains by car and ending the isolation of resorts once reachable only by trail. Roadhouses like Newcomb’s Ranch became iconic gathering places. The road is also well-known in popular culture, having appeared in numerous car commercials and films.

Its state and national scenic designations ensure that development along the corridor is limited to preserve views. Despite dangers from sharp curves, steep drop-offs, and sudden weather, the route remains one of California’s most beloved mountain drives.

Dual timeline showing both the historical/social milestones and the engineering/construction milestones of the Angeles Crest Scenic Route (State Highway 2).

Historical and Social Milestones
1900s–1910s – Local boosters push for a mountain road to open the San Gabriels for tourism and firefighting.
1919 – J.B. Lippincott surveys a high-ridge route for the Automobile Club of Southern California.
1929 – Construction begins under the Division of Highways.
1932 – First section opens to Red Box Saddle; hiking culture gives way to car tourism.
1930s – CCC crews and prison inmates contribute to construction.
1941–1945 – Work halts during World War II.
1956 – Full 66-mile route opens to Big Pines and Wrightwood.
1971 – Officially designated a California State Scenic Highway.
1978 – Landslide severs SR-2 and SR-39 connection; never restored.
1990 – Designated a National Forest Scenic Byway.
2009–2011 – Station Fire and storms destroy sections; road reopens after $32 million repair.
2020 – Bobcat Fire causes closures.
2022–2023 – Historic storms wash out major segments.
2025 – Full highway reopens after $7.9 million rebuild.

Engineering and Construction Milestones
1919 – Survey establishes a route with ≤6.5% grades and 300-foot-radius curves for safe mountain driving.
1929 – Initial grading begins near La Cañada; crews use hand tools, dynamite, and heavy machinery.
1930s – Road cuts as deep as 240 feet carved into mountainsides; bridges built across gullies.
1930s–1940s – Prison labor camps established; inmates from San Quentin and Chino work alongside contractors.
Late 1940s – Twin tunnels bored near Islip Saddle (680 ft and 470 ft long).
1950s – Dawson Saddle reached at 7,901 ft – the highest highway pass in the San Gabriels.
1956 – Last segment tied together; route spans 66 miles from La Cañada to Wrightwood.
1978 – Landslide permanently removes SR-39 connection.
2009–2011 – Culverts, retaining walls, and roadbeds were rebuilt after the Station Fire and debris flows.
2022–2025 – Major slope stabilization, drainage replacements, and retaining wall construction along Islip Saddle–Vincent Gulch.