Unless you’re a radio engineer, you may not care about this.
For a long time, I’ve had the ability to show “Nearby” licensees – and the listing was sorted by distance.
Let’s say you wanted to see where the transmitter is for WLUP-FM in Chicago, and what other stations are nearby (if distance is 0.0, then they are sharing the same tower). Click on the Nearby icon wherever you’re seeing it: 
http://streamingradioguide.com/nearby-transmitters.php?stationid=10668
Surprise Surprise Surprise!
This “tower” has transmitters for 9 FM radio stations, and 3 Digital TV stations. If you click on the tower icon, you can figure out the “tower” is the John Hancock building. The cluster of other stations about 1.5 miles away are on the Willis Tower, which will forever be called the “Sears Tower” by the natives.
Now you have two new options for the sorting. The “list” of what you see is controlled by the distance setting in miles at the top. Imagine a circle drawn with a radius of nnn miles with the selected station in the middle.
If you click on the Frequency heading, it will sort by Frequency. The station you are “centered” on stays at the top and has a light blue background to remind you where you are. TV, FM and AM sort out separately.
If you click on Freq +/-, that shows you the stations (within your imaginary circle) that are closest in frequency to your target station.
Let’s say you were trying to listen to KDKA-AM at night on 1020 kHz on your C Crane Radio (over the air, not streaming!), and some other station is interfering with their signal.
http://johngalt.streamingradioguide.com/nearby-transmitters.php?stationid=343
If you go out to 100 miles, the station closest to 1020 kHz is WZSK-AM about 100 miles away on 1040 kHz – it’s a daytime station, but sometimes transmitters fail to shut themselves off at the correct time.
If you make the circle 1000 miles, you’ll find a few stations on 1020 in the Midwest (beyond 800 miles) that don’t go off at sunset. The KDKA nighttime signal is non-directional – but since the Reagan era at the FCC, “clear channel AM” stations” no longer have a claim to be “protected” on their night time “skip”. You probably can still hear the KDKA in Florida at night in a quiet location, but protecting KDKA is no longer the FCC’s priority in managing license spectrum.
The stations on the “next door” frequencies (1010 or 1030) are the most likely to be the source of the noise (unless it is the Section 15 station being run by a teenager down the block)… There is a station on 1010 in West Virginia about 100 miles away from KDKA (not from you!) that is supposed to cut back to 17 watts at night…. 1010 was not a “Clear Channel frequency” – it is the frequency of CFRB-AM in Toronto, Canada. 1030 (on the other hand) was the clear channel AM frequency for WBZ-AM in Boston. Depending on where you live back in the AM DXing days, those two stations would invariably rise and fade over each other.