Having drawn donors for years in CO at elevation, we would have had problems with an upper limit. In fact, physicians would sometimes recommend donation for those people who may have a high H/H due to the elevation and no other reason. If donors mentioned this to us, we very clearly asked if they were diagnosed with polycythemia or hemochromatosis. If the answer was no, we accepted them for donation. BTW, we had a noncompliant polycythemia patient that would occasionally come in with a hematocrit of 70%.