Answer : Mine Train Thru Nature's Wonderland  Frontierland, Disneyland, 1960-1977

Big Thunder Mountain and the Big Thunder Ranch are on top of the old mine train. Parts of Rainbow Ridge remain as the town which Big Thunder RR pass at the end of the ride. There are a number of tributes to the old ride as part of Big Thunder, thanks to the work of Tony Baxter, the designer of the replacement ride.

Cascade Peak remained for years, but is no longer, having been bulldozed and removed by Disney several years ago. One train rots quietly along the banks of the river where Cascade Peak used to be. Marmots pop up out of the lone car. The Bear River trestle also remained for years but was wiped out in a small landslide after a rain storm. The little lake the bears swam in remains, even if the bears do not, and sometimes a fish mechanism jumps, the sole reminder of Bear River.

Big Thunder Ranch still has some of the rock work, although the whole thing was covered with about six feet of dirt, so the real attraction is buried below where you walk. Many of the animals which were in the attraction were too broken to be salvaged, so they are buried beneath that dirt. It would be a strange archeological dig someday.

info courtesy of http://www.keeline.com.

Big Thunder Mountain Railroad debuted at Disneyland on September 2, 1979. It was built on the site of the "Rainbow Caverns Mine Train", which later became "Mine Train Through Nature's Wonderland" before it was replaced by Big Thunder Mountain Railroad. The buildings from the town of Rainbow Ridge are now part of Big Thunder town.

info courtesy of http://allears.net.