[time-nuts] WWV / WWVB Reference Feed

[DON MURRAY]

Hello all...
I have a question that I have been unable to answer,and I am sure one of the learned time-nuts will havean instant answer for me!
During my searching for an answer to my question, I 
learned that there is an NIST Facility at Boulder, CO 
that has a 4 Cs Ensemble that is the frequency reference 
for the WWV and WWVB transmitters at nearby Ft. Collins.
My question: how is that reference transferred from the NISTfacility to the WWV / WWVB transmitter site?
For some reason, I was under the impression that the referencefrequency for the transmitters was locally generated at Ft. Collins.
I have searched around for the answer, but have come up emptyhanded.
TNX to anyone who might have the answer!

73DonW4WJ