Considering that Tesla launched the SC network less than 3 years ago, it is an impressive accomplishment indeed, despite complaints from some quarters.
The build out will continue, and there is still absolutely no sign that any other car company plans to do anything remotely close to the Tesla SC network. That continues to surprise me.
I am in the middle of a 3,400 mile road trip in the western United States, and the SC network has worked very well for me.
The Tesla website now reads 500 Superchargers. No Fountain Valley.
Supercharge.info, which I don't think is official but rather user-sourced, also shows 500 with the 500th being open in Moers, Germany today. Supercharge.info has Fountain Head under construction and a total of 211 in the US.