Mare Island, near San Francisco, is the oldest course west of the Mississippi, being established in 1892 as a 9 holer. Robin Nelson recently extended the course to 18 holes.
I believe it has been suspected that there was some sort of Mackenzie involvement in modifying the old nine holes, but that it has only been rumour and hearsay. Well I have now found a newspaper article from the Oakland Tribune dated 26 September 1929 that confirms Mackenzie did indeed visit the course in September of that year with a view to planning a revised course due to train line and ammunition bunker intrusions proposed for the land where the existing course lay.
The club history section on their website indicates the course was revised in 1933 due to encroachment of ammunition bunkers - as per the newspaper story - but does not say who, if anyone, was the architect of that revision. Is it possible that Mac did draw up plans for the revised course and that these were eventually implemented? Hopefully one day we can find out more.