In addition to the other responses there is another possibility.

If you were listening to one of the nets; Intercon, Maritime Mobile,
etc. it was likely a station offering assistance to net control so that
the net control could recognize or honor the mobile station's request.

A Minnesota station would not be normal 'DX' but may have been operating
from an Island or Lighthouse or Museum Ship etc. In this situation I
would not honor an assisted QSO. [Note to the DX purists: I have worked
DX on the DX nets but never QSL'd an assisted contact].

Deacon Dave, W1MCE

Harry George wrote:
Newbie question: This morning on 20m I was listening to a pileup for a
mobile in Minnesota who was 33 from my G5RV near Seattle. I could
hear some of the callers but not many. Suddenly a very strong signal
came on offering to relay for the mobile (I think). It was very rapid
fire for quite a while, and then the strong signal bowed out and
someone thanked him for the help.

It was all happening to fast for me to follow. What was I hearing?

KD7VEY