Well, I missed one: Providence & Worcester. Publicly traded. So here's an updated list, all as of 12/11/2015 close. If anybody knows of other Canadian publicly traded railroads (besides CN and CP), please add in the comments.
Symbol Name Exch Common Divs? Yield
UNP Union Pacific NY $77.28 Yes 2.85%
CSX CSX Corp NY * $25.72 Yes 2.80%
NSC Norfolk Southern NY $89.44 Yes 2.64%
KSU Kansas City Southern NY $74.63 Yes 1.77%
CP Canadian Pacific NY *** $123.47 Yes 0.85%
CNI Canadian National NY *** $52.73 Yes 1.75%
GWR Genesee & Wyoming NY ** $51.21 No div
PWX Providence & Worcester NASDAQ $13.41 Yes 1.19%
PRRR Pioneer Railcorp OTC ^ $7.95 Yes 1.26%
(priv) BNSF (see BRKa, b) (private) n/a n/a n/a
* Moves to NASDAQ on 12/21/15
** Also on NASDAQ
*** Also on Toronto exchange
^ Pink Sheets