While I received copies of articles from the May, 1916 El Paso Herald from the public library (because no library in Austin has this edition), I wanted to read more. I figured since most of the articles were from the AP and the Glenn Springs raid was big news, I'd find the story in other Texas Newspapers. First up, the San Antonio Express.
From the May 8th, 1916 Edition. Pg. 4,
"The officials of the International Mines Company have placed all of their equipment, which consists of more than one hundred mule teams and several motor trucks, at the disposal of General Funston."
Two things:
1) We now have an idea of how large an operation this was. 100 mule teams? That's one team less than every mile (The ore terminal is roughly 80 miles away from Marathon). This gives a good idea of how much traffic went up what's now known as the Old Ore Road. Driving on the Old Ore Road today, it's hard to believe there was ever a store near the Ernst Tinaja, but with that kind of traffic, I can begin to see that this place was much busier than it now is.
2) Note the name: International Mines Company, not the International Mining Company. I don't know if this is significant, but I assume the reporter got the name wrong. He got other things wrong in this article, like the location of the mines (on the US side, according to him).
From the May 9, 1916 San Antonio Express, Pg. 1
"An old tramway employee known as "Nick" escaped and after wandering forty miles afoot, was brought into Marathon at midnight by Lloyd Wade, a border rancher.
"'Nick' says the bandits declared they would take their prisoners to Laguan to see "Villa." Presumably they meant the Laguna on the Mexican central above Chihuahua."
"...Forty American troopers and cowboys crossed the river into Mexico at noon today at Boquilla [sic]. Among them are Sheriff Watson and Customs Inspector Ryan. They are hurrying to the aid of seven American employees of the Puerto Rico Zink [sic] mine, fourteen miles below Boquilla [sic]. At Boquilla [sic] the raiders said they were going in the mines to kill every "gringo" there."
So, "Nick" is most likely Nick Postrius, who's story appears in the El Paso Herald. 40 miles is a tough hike in this terrain, he probably went up the Old Ore Road and made it halfway to Marathon before he got picked up.
Additional information: Customs Inspector Ryan is a new name and may have worked at the Ore Terminal. Also, the writer, Joseph Timmons of the International News Service, can't spell.