Over the past 20 years have made several trips to the Islands on business and pleasure. In general I found a surprisingly large amount of evidence of railroads on Oahu and Maui. The keen eye can pretty readily find grades, bridges, buildings, and occasionally rail. On Oahu in particular there is a lot of track on the west side still in place, much of which is used by the museum located west of Pearl. The books by Best and Hungerford are very helpful references if you can find them. When Uncle Sam sent me there briefly in the 60's, the Oahu was still switching in Honolulu as Coker described. What intrigued me about the Oahu operation was the cantilever masted block signals still in place over what had been a double track mainline... was that the only block signalled narrow guage in the U.S.???? There was (is?) a nice old terminal station in downtown Honolulu.