If you hike up Old Woman from the bottom, just over a mile up the canyon from the parking area at Garvin's Chimney, there's an old mining road that climbs out of the canyon on the left side. Just hike up that old road about a mile to the inscription. There are a couple of other inscriptions at the same spot.
This map shows the start of the mining road and the location of the H.C.L. 1901 writing.
H.C.L. 1901
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1901 D.T.T.
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