| St. Louis & Chain of Rocks R.R. | Saint Louis, MO | |
| St. Louis Iron Mountain & Southern Ry. Co. | Jackson, MO | www.slimrr.com |
| St. Louis Steam Train Association | Saint Louis, MO | |
| Salamanca Rail Museum | Salamanca, NY | mysite.verizon.net/bizxyrad/salamancarailmuseumassociation/ |
| Salem & Hillsborough R.R. | Hillsborough, NB | |
| SAM Shortline Excursion Train | Cordele, GA | www.samshortline.com |
| San Bernardino Railroad Historical Society, Inc. | Torrance, CA | www.sbrhs.org |
| San Diego & Arizona Railway | La Mesa, CA | www.psrm.org |
| Santa Fe Southern Railway | Santa Fe, NM | www.thetraininsantafe.com |
| Seashore Trolley Museum | Kennebunkport, ME | www.trolleymuseum.org |
| Shasta Sunset Dinner Train and McCloud Railway Company | McCloud, CA | www.shastasunset.com |
| The Shelburne Falls Trolley Museum | Shelburne Falls, MA | www.sftm.org |
| The South Carolina Railroad Museum, Inc. | Winnsboro, SC | www.scrm.org |
| South Coast Railroad Museum | Goleta, CA | www.goletadepot.org |
| Southern California Railway Museum, Inc. | Perris, CA | |
| The Southern Michigan R.R. Society, Inc. | Clinton, MI | www.southernmichiganrailroad.com |
| Southwest Georgia Excursion Train | Cordele, GA | www.samshortline.com |
| Southwest Georgia Railroad Excursion Authority | Cordele, GA | |
| Steam Railroading Institute | Owosso, MI | www.mstrp.com |
| Steamtown National Historic Site | Scranton, PA | www.nps.gov/stea |
| Stevenson Depot Museum | Stevenson, AL | www.stevensondepotmuseum.com |
| Stuhr Museum of the Prairie Pioneer | Grand Island, NE | www.stuhrmuseum.org |
| Sumpter Valley Railroad | Baker City, OR | www.svry.com |
