Ed,
A good place to start on the Big Island is at the Railway Museum that has already been mentioned here. Its near Lapahouhou Point (sp) on the north shore.
The museum is on the south side of the main road as you head for Hilo. You will know it’s the right place because they have a small Plymouth locomotive out front that members of been working on.
The museum is in an original Hilo RR building behind the original station platform that now runs next to the road. The ladies inside where very helpful in pointing me in the right direction to find the railway remains and they had a very nice collection of pictures, videos and artifacts pertaining to the history of Island railroading.
Nearly all of the main road along the north shore of the Big Island is on top of the railway grade. At lease two of the original steel railway bridges now carry the highway but you would never know that unless you see the bridge from below which is easily done by taking the turn offs at the end of the bridges.
The old highway is also a very scenic drive and worth a trip but it has nothing to do with the railway.
In Hilo, you can also see the old Hilo Railway roundhouse. It’s used as a Semi truck shop right now. I can’t give you directions to find it but the folks at the museum can.
Hilo is not very large. If you find the large community building that houses the city swimming pool, the roundhouse id just behind it. The roundhouse has about 7-9 stalls and is built of concrete.
The Hilo Railway must have been a very scenic line in its time. Too bad it was 4’8.4”
Well, I guess no railway can be perfect,….. except maybe the RGS of course.
Hope this help a little Ed,
Have a good trip.
Tim