A Special Interest Group (SIG) is
an independent, not-for-profit, membership group organized to
provide a forum for the exchange and collection of railroad
prototype and/or model railroad information about specific
topics. SIGs include: American Civil War Rail Road Historical
Society; American OO Gauge SIG; Baltimore & Ohio
Historical Society; Burlington Northern, Friends of the;
Burlington Route Historical Society; Canadian National
Railways Historical Association; Canadian Pacific Historical
Association; Cane SIG (Cane Railway Modeling SIG); Chicago
& North Western Historical Society; CMRI SIG; ETE
(European Train Enthusiasts); Friends of the East Broad Top;
Frisco Modelers Information Group; Great Northern Historical
Society; Layout Design SIG; Missouri Pacific Historical
Society; MSS (Modular Signal System) SIG; NTRAK Modular
Railroading Society, Inc.; O Scale Kings; Operations SIG;
Proto:87 SIG; Railroad Industries SIG; Railway Signaling
Technical and Historical Society; Rock Island Technical
Society; S Scale SIG - SSS; Shore Line Interurban Historical
Society; Steel Mill Modelers Special Interest Group (SMMSIG);
Toronto, Hamilton & Buffalo Historical Society; and TT
Scale SIG.