I'm working now on the data and bio of your Ype Ypma on FindaGrave, # 70223869, so please look there. If you have additions I would to hear that of course. It's my intention to link at FAG all his deceased children to him, complete their data and create a bio for them.
Greetings from the Netherlands,
P.S. How are you related to him? I'm not related to any Dutchy in Montana; since a few months I have become very interested in the Dutch settlement Holland, later called Amsterdam-Churchill and I want to investigate for the long term all the Dutch families here until about 1950, connect them to their ancestors in the Netherlands and complete their data and bio.