D&RG Ry construction force larger than US Army

July 23, 1881 Rico, CO Dolores News
Thirty-two Thousand Laborers.
“The force of men now at work on the D&RG Railway’s extension is larger than the United States army!”
“ How many men are there?” asked the Tribune reporter a little awed by the statement.
“More than 32,000”, returned the Governor, laconically. “Nearly 19,000 of this number are at work in Old Mexico. There are 3,000 or 4,000 in New Mexico, 5,000 or 6,000 in this state, and the remainder are scattered through Utah and other localities, where they are now doing work.”

What was the D&RG building in Old Mexico? This was just as the line was about to enter Durango and Del Norte.