SD3R
San Diego 3-Railers layout at the San Diego Model Railroad Museum, Balboa Park- San Diego, California

SDMRM
San Diego Model Railroad Museum in Balboa Park, San Diego, California

TTOS-Southwestern Division
Toy Train Operating Society - Southernwestern Division

TTOS-SP
Toy Train Operating Society - Southern Pacific Division

San Diego S-Gaugers
An "S" Gauge model train group located in San Diego, California

The Gilbert Gallery.org
A website dedicated to American Flyer S-Scale Model Trains