Century training routes starting from Long Beach?

I'm training for my first century ride (100 miles) in October and I'm looking for good long-distance training routes starting from Long Beach.

I've been doing the San Gabriel River Trail out-and-back which is great for distance, but I'd like to add some variety. Anyone have recommendations for 40-60 mile routes that start in Long Beach?

I'm comfortable on roads and bike paths. Not worried about elevation since Long Beach is flat, but I want routes with minimal stopping and decent road surfaces. Also curious about good turnaround points with food/water.