Not hard to confuse the newspaper man at Alamosa

Alamosa Journal Railroad Notes: April 7, 1905:
"The car repair department is busy transferring a whole row of flat cars from standard gauge to narrow gauge for use on the new narrow gauge line from Durango to Farmington."

Two weeks later they were back in gage:
Alamosa Journal Railroad Notes April 21, 1905:
"A new standard gauge engine was loaded on flat cars at Alamosa this week to be hauled west for the use on the Durango - Farmington Branch".

Very likely those 8 flat cars had their standard gauge truck tied down on their deck. See the RGS Story Volume XI for 17 pages of photos, maps, roster and history about the 3 rail section of Durango and SG to Farmington.