You are on the BNSF Cuba Subdivision which runs from Valley Park, Mo to Springfield, Mo.
There are two different channels used for voice,
AAR 70 161.160 is used from Lindenwood yard in St. Louis to Rosati
AAR 16 160.335 is used the rest of the way to Springfield
There are also 2 frequencies used for ATCS communications, you will hear these as short data bursts,
AAR 07 160.215 which is used from Valley Park to Stanton, Mo
AAR 57 160.965 which is used the rest of the way to Springfield.