Data downloaded directly from the NOAA website. Datum information also downloaded. NOAA Primary Benchmark is 34 1923 4.77m above TGZ.
Documentation added 2011-08-11
Using data from NOAA the RLR diagram was re-drawn. Primary benchmark appears to be 34 1923 4.770m above gauge datum. The historical benchmark BM 27 previously used by PSMSL no longer appears in the NOAA report.