These are Steel Indent Nails. Some of them are marked "Unknown". If you have any information on those nails, or find a discrepancy, please e-mail me.

Buffalo, Rochester & Pittsburgh RR (Ash)	Buffalo, Rochester & Pittsburgh RR (Ash)	Southern Pacific RR	Pennsylvania RR	Des Moines & Central Iowa RR	Southern Pacific RR
Chicago, Burlington & Quincy RR (Red Birch)	Pennsylvania RR	Pennsylvania RR	Beech, Buffalo & Rochester & Pittsburgh RR	Beech, Buffalo & Rochester & Pittsburgh RR	Pennsylvania RR
Buffalo, Rochester & Pittsburgh RR (Black Oak)	Buffalo, Rochester & Pittsburgh RR (Beech)	Buffalo, Rochester & Pittsburgh RR (Beech)	Pole Nail      St. Louis, MO	Southern Pacific RR	Indiana-Michigan Electric
Pennsylvania RR	Cedar Falls, Iowa	Buffalo, Rochester & Pittsburgh RR (Cherry)	Buffalo, Rochester & Pittsburgh RR (Cherry)	Dierks Treating	Pennsylvania RR
Southern Pacific RR	Pennsylvania RR	Southern Pacific RR	Chicago, Burlington & Pittsburgh RR	Southern Pacific RR	Southern Pacific RR
Los Angeles Gas & Electric California	Los Angeles Gas & Electric California	Southern Pacific RR	Southern Pacific RR	Unknown	Unknown
Buffalo, Rochester & Pittsburgh (Hickory)	Buffalo, rochester & Pittsburgh (Hickory)	Southern Pacific RR	Unknown	Indiana & Michigan Electric	Southern Pacific RR
Unknown	Kansas City Electric	Lincoln Gas & Electric; Lincoln, NB	Buffalo, Rochester & Pittsburgh (Maple)	Buffalo, Rochester & Pittsburgh (Maple)	Buffalo, Rochester & Pittsburgh (Maple)
Unknown	Northwestern Electric Portland, OR Vancouver, WA	Northwestern Electric Portland, OR Vancouver, WA	Nebraska Power Company Omaha, NE	Nebraska Power Company Omaha, NE	Nebraska Telephone Company
Buffalo, Rochester & Pittsburgh (Pine)	Buffalo, Rochester & Pittsburgh (Pine)	Buffalo, Rochester & Pittsburgh (Pine)	Buffalo, Rochester & Pittsburgh (Pine)	Peoples Light Co. Davenport, Iowa	Buffalo, Rochester & Pittsburgh (Pine Oak)>
Public Utilities Comm. North ST. Paul, MN	California	Buffalo, Rochester & Pittsburgh (Red Oak)	Buffalo, Rochester & Pittsburgh (Red Oak)	Buffalo, Rochester & Pittsburgh (Red Oak)	Buffalo, Rochester & Pittsburgh (Red Oak)
California Edison	California Edison	California Edison	California Edison	California Edison	California Edison
California Edison	Unknown	Santa Fe (Steam treated)	Pennsylvania RR	Unknown	Utah Power & Light
California	Unknown	Unknown	Buffalo, Rochester & Pittsburgh (White Oak)	Unknown	Santa Fe (Substandard/Inferior tie)
Santa Fe (Substandard/Inferior tie)	Santa Fe (Substandard/Inferior tie)	Santa Fe (Substandard/Inferior tie)	Santa Fe (Zinc-chloride)	Santa Fe (Zinc-Chloride)	Santa Fe (Oil-Zinc)