A veteran UPY 691 (GP15-1) waits for a mate to pair up and then will sort cars in the Union Pacific's North Yard in Denver, Colorado.
A number of Union Pacific SD40N (former SD40-2's) are currently working in the North Yard sorting freight cars throughout the day.
BNSF 7147 (ES44C4) leads a windmill blade train through the Black Forest in Larkspur, Colorado.
Helper engine BNSF 9216 (SD70ACe) waits on a siding at Union, Colorado to assist any train that might need help getting over the Palmer Divide.
BNSF 6100 (ES44AC) leans into the elevated curve at Keenesburg, Colorado.
After running through Little Ten Curve the California Zephyr rounds the base of Big Ten Curve which will elevate the train to the track seen in the background.
After picking up two private Patrick Henry cars at Denver Union Station, the California Zephyr headed west and is seen here navigating Little Ten Curve as it starts its climb into the Colorado Roc... (more)
Amtrak engine 71 (P42DC) leads the California Zephyr through Wiggins, Colorado at sunrise.
BNSF 6256 (ES44AC) heads towards the bright morning sun as it pulls a freight through Wiggins, Colorado on the Brush Sub.
With only a few minutes of sunlight left, BNSF 6170 (ES44AC) leads a loaded coal train through Castle Rock, Colorado.
BNSF 5152 (Dash9) leads a freight through light snow and heavy fog at Plainview, Colorado as it heads towards Denver.
BNSF 8752 (SD70ACe) passes an idling helper ACe in light snow as it leads a loaded coal on the Joint Line through Union, Colorado.
BNSF 8117 (ES44C4) leads a GEO train through Douglas County on the Joint Line past the Comcast satellite facility.
The California Zephyr casts a reflection on the glass-smooth surface of Barr Lake as it runs through Brighton, Colorado on the Brush Sub at dawn.
The California Zephyr runs along the hills on the Moffat Tunnel Sub west of Rollinsville, Colorado.