Would be good if we could use their full name instead of an abbreviation. I assume it's the person in this photo https://www.summitpost.org/pierre-de-st-croix-on-pitch/141569 so perhaps Pierre de St. Croix?
We can always add J.P. as another name in the meta data.
I had a good look - in my library as well as online - I had wondered about his name and his nationality. Other than he also worked as a park ranger in the pacific NW in the later 70s I drew a blank. He was always referred to as JP. TM Herbert is similar and it appears he was actually named TM. Judging by the helmet, the photo is from the 00s so may not to be the same person.
Thanks for digging around, looks like we're sticking with J.P. for the moment, perhaps not a bad thing if that is how he was generally known https://climbing-history.org/tools/style#terminology-naming-and-grades-climbers-name
Found him in Alpinist. Searched for various Jean-plausible name de St. Croix climber and got a hit. https://alpinist.com/features/76-visions-of-charlie-porter/
Top work! I've added j.p. as a nickname in case people are searching for that on ch.
Good idea. AAJ references to him use J.P. even when using full forenames for others in the same report, so very possibly a nickname.
https://publications.americanalpineclub.org/articles/12198416302/
https://aac-publications.s3.amazonaws.com/documents/anam/1980/PDF/ANAM_1980_4_3_040b.pdf
Nothing to confirm nationality but given he was a US gov. employee it seems most likely he was American. Same heritage as Yvon Chouinard perhaps!