In doing a conventional search a while back, I came up with 157.360. The traffic is digital and I just heard today someone (trooper?) say they were on I-29, mile marker 99. That would put it a mile north of Del Rapids, and in the coverage of the Baltic tower. BUT, the database doesn't show 157.360 on the Baltic or any other tower. Perhaps this frequency has been added to the Baltic or another nearby tower? I initially thought I had stumbled on an input frequency, but it's too active and the signal is too good for that. I'm guessing it's part of Baltic or maybe Sioux Falls. Anyone have any info?