Anchor uses open fermentation in clean rooms using cool San Francisco air so we depart from their methods there so why not hops and yeast.
The guidelines basically describe Anchor Steam Beer. So, because Fritz Maytag chose Northern Brewer in his resurrecting the style we’re kinda stuck. Despite the Anchor choice, I find it interesting that, in a 2010 BYO article, Jamil said “Historically the hops would most likely have been California-grown Cluster hops.”
He goes on to say, “I have always thought Spalt would work well, with its interesting spicy and somewhat rustic character. You might also experiment with Cluster, Nugget, Perle, Santiam, Tettnanger or Liberty.”
The 34/70 yeast is an interesting choice. Interesting how close it is genetically to 2112 and WLP 810.