Curious about that PK on the crest? Wikipedia:

Before the Pittock Block was built, the site was occupied by the home of Henry L. Pittock, the publisher of The Oregonian. Pittock was preparing to move into the Pittock Mansion and leased the entire block to a California investor with the requirement that a "worthy" building named after Pittock would be built on the site.

Still curious about that PK? So am I. First letters of Pittock, perhaps.