RV route guide
I-15 Cajon Pass — California LA-Vegas corridor
5-6% sustained. The LA-Las Vegas RV corridor's main mountain crossing.
I-15 between San Bernardino and Hesperia crosses Cajon Pass (3,777 ft). The grade is 5-6% sustained both directions. Cajon is one of the busiest mountain passes in the US — traffic between LA, Las Vegas, and the Inland Empire converges here. The grade is manageable in any RV with attention to engine braking.
- Tier
- Clearance + restriction
- State
- California
- Sources
- Cited official (.gov / .org)
Is I-15 Cajon Pass hard on RVs?
Moderately. The 5-6% grade is less steep than I-5 Grapevine but the route carries heavy traffic and the climb is sustained. Use engine braking on the descent. Watch for weekend traffic backups. Weekday transit is much smoother.
- 5-6% sustained grades
- 3,777 ft summit
- Heavy weekend traffic
- Use engine braking on descent
- Manageable in any RV
Practical advice
I-15 Cajon Pass is the LA-Las Vegas RV corridor. Most LA-area RV travelers heading to Las Vegas or Utah cross Cajon. The route is interstate-grade, well-maintained, and has multiple exits with fuel and food.
Weekend traffic is heavy — Friday afternoon LA-bound, Sunday evening Vegas-bound. Plan weekday transit if possible.
What Caltrans doesn't tell you
Cajon is a well-engineered modern interstate pass. Less dramatic than Grapevine, but still warrants engine braking attention.
- Caltrans QuickMap: Live status.[source]
Frequently asked questions
- Best time to cross Cajon?
- Mid-morning weekdays. Avoid 4-7 p.m. and Friday afternoons.
Authoritative sources
Verify current conditions with state DOT 511 systems before departure. RV restrictions may change. Weather may close roads.
Planning an RV trip along I-15 Cajon Pass?
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