The Yerex's are a prolific bunch as far as I've been able to find out. I've not done a lot of research on the name, but there are some pretty interesting characters there.
One Yerex you might like to chase around was a fellow who started a South American airforce which later developed into a multi-nation airlines. He was a sort of soldier-of-fortune who was flying a bush plane in New Zealand before he went to Argentina.
Because I haven't really pursued the family genealogy a lot, I can only tell you about my own branch of the family, the stories I've picked up and about my own family branch.
I'm a retired soldier myself and hold (along with thousands of others) the Nobel Peace Prize of 1988. I have three grown sons and two lovely little granddaughters.
The story that I've heard over the years is that the family was originally made up of European settlers in the United States, and in fact some of the Yerex pioneer men took native women as wives. My own Great grandmother was of the Snake tribe of Colorado, near the Snake River.
Others in the family, as the story goes, were United Empire Loyalists who lost everything they owned at the time of the American Rebellion (or "American Revolution") around 1776 and moved North to Canada to remain loyal to the British crown, i.e., King George the Third. I'd be interested in finding out if this story is true.
I myself was born on the West Coast of Canada, in Vancouver, but the main part of my branch is located up and down Vancouver Island. We have relatives from Victoria to Comox, and although I haven't had much contact with them, I think Vancouver Island could be called the Western Home Office for Yerex's.
I'd like to swap stories and information with you if you're intersted. I've asked this website to notify me of replies to my post, so contact me if you like through this medium.