Jim
the line reached Prairie City (mp80.1) in 1910, then 1929 the line was abandoned to Bates, mp 60.2, and that was the terminus until total abandonment in 1947.
Estimates range from many hundreds to several thousands of miles of 3-foot logging spurs that were all connected through the years to SVRy.
Most anywhere you walk in the Wallowa Whitman or Malheur National forests between Sumpter Valleya nd PC you will run across rr grade, heck if your luck you just might find the lost locomotive
)
Come on up sometime and visit us.
Ron B
SVRR