If you set your scanner to scan all the channels between 160.080 through 161.980 you should be able to find some active RR frequencies (and alot of other chatter from users outside the RR industry).
Or hang out with railfans and jot down their frequency numbers.
You are not going to hear much of anything, except garbled sporatic transmission bursts, and defect detectors if they are nearby.
Some States have local laws against recievers (even though they can not transmit) as you can use the information for personal gain, which in some very rare localities that wish to prosecute is a crime. Railfanning on RR property with the use of a scanner receiver can add to the local RR cops disdain for, ie: railfans/loitering/trespassers.
