On 16 April 2000 I visited the Redwood Valley Railway Corporation situated in Tilden Park Berkeley California. The same location is also home to the Golden Gate Live Steamers - but they were not running today, their club locomotive had broken down :-(.
The Redwood however, was alive and well. The railway is (I think) 15" gauge . Their locomotive roster consists of Baldwin models and a model narrow gauge freight train with seats built in to carry passengers. The group claim to emulate an old time narrow gauge feel, and I tend to agree. The ride is quite long by model standards - 12 minutes at about double walking pace. With a couple of wooden trestles and a tunnel. The line is built as a dogbone with some spurs for additional running (mostly shunting). The standard of their line is amazing, far in excess of anything I have encountered in Australia. The line is real track, the running sheds are good replicas of their prototype. They even have an operating water tower along the line.
The railway has a web page at http://www.redwoodvalleyrailway.com/
The models of both the train and the locomotives are very exact in their detail and pleasing to the eye. The large steamers produce some good power. The locomotive which pulled us was a 2-6-0 and pulled a train of 14 gondola cars and a caboose (hey, I'm in the USA, might as well talk like them :-).
My boys enjoyed themselves immensely, although my (then almost) four year old got grumpy when it was time to get off!.