A pair of MAC's work the East Yard in Longmont, Colorado.

Executive MAC BNSF 9621 has just dropped off a freight into the BNSF's yard in Longmont, Colorado.

An early morning freezing fog has coated the trees in ice, making for a colonnade of frozen trees along Atwood Street in Longmont, Colorado.

One of the many sand trains that move through the Colorado Front Range hi-balls through Longmont, Colorado. The sand is used in the fracking process in order to extract more oil and natural gas fr... (more)

BNSF 8900 runs down Atwood Street in Longmont, Colorado, pulling a freight from Fort Collins. The upside down writing on the jeep windshield says "If you can read this flip me over!"

BNSF 6725 (ES44C4) passes the historic Longmont Depot and crosses Main Street as it works its way through Longmont, Colorado. The depot was built in 1898 by the Colorado and Southern Railroad and... (more)

Three BNSF units strain to pull a heavy freight through Longmont, Colorado.

After completing its work in the Longmont Yard, BNSF ES44C4 #6904 leads the Denver to Cheyenne manifest up the grade and down Atwood St in Longmont, CO on December 17th, 2018.

BNSF 6725 (ES44C4) leads a freight through Longmont, Colorado. It will travel through Niwot, Boulder, Louisville, Broomfield and Westminster on its way to Denver.

BNSF 6725 (ES44C4) leads a freight through Longmont, Colorado.

In the crisp cold air, the brakeman on the "Buck Local" is about to enter the depot in Longmont, Colorado, where the conductor is also grabbing some paperwork before heading south to Bou... (more)

Some light snow has started to fall as BNSF ES44AC No. 5812 leads the Denver-Laurel manifest up Atwood Street in Longmont, Colorado, on November 11, 2018.

The brakeman on BNSF's Buck Local led by BNSF GP50 No. 3160 gets ready to sweep snow off the "GW Switch" before lining it reverse so the local can enter the main in Longmont, Colorado, o... (more)

These matching MAC's were spotted idling at the depot in Longmont, Colorado.

In the dawn hours of a cool and overcast morning, BNSF C44-9W No. 5018 leads a northbound loaded sand train up the middle of Atwood Street at Longs Peak Avenue, in Longmont, Colorado, on November ... (more)