FATMAP difficulty grade
This is a complete traverse of the Santa Monica Mountains on a single trail, the Backbone Trail.
Therefore, the route is rad! It is one of my favourite runs that I have done in the US, hands down.
You get views of the mountains and the Pacific Ocean along much of the course.
And, the vegetation, smells, and sounds are distinctively SoCal! The route is fairly straightforward.
It follows the same trail throughout the entire route.
That said, there are many trails that intertwine along the Santa Monicas so having a good study of the route beforehand, and reviewing at junctions could be of benefit! It is a point-to-point route so having someone pick you up at the other end would be great!