The railroad you seek in McKinley County is the Atchinson, Topeka, and the Santa Fe. Also known more commonly as the "Santa Fe", or the "AT&SF". I am not familiar with the name Alsbrooks, but can tell you railroad employment brought mnay new citizens to Gallup in the period 1881-1925.

The AT&SF is, and aways has been, Gallup's only rail link. Gallup is located on the main line of the Santa Fe and was founded by the AT&SF in 1881 as a railroad construction camp. The town is named after David Gallup, the AT&SF Paymaster of the original construction camp.

"Frisco" refers to the Santa Fe's use of "the Frisco Route", a slogan painted on the side of all their rail cars for many, many decades as an advertisement of freight and passenger service to the San Francisco, CA area. The "Frisco Route" was an advertising slogan of the AT&SF.

Gallup is located on the "Frisco Route" and its fortunes were directly tied to the AT&SF for 65 years. Gallup is still a railroading town and a regularly scheduled stop for all train traffic. The AT&SF has been ranked in the top five largest railroads in the U.S. since 1870. The Santa Fe ran from Chicago to Los Angeles, then up the Pacific coast to the SF
Bay area.

The AT&SF was acquired in the mid 1990's by the Burlington Northern Railroad and it operates today as the Burlington Northern Santa Fe, or BN&SF.