A 79-car Union Pacific MRONY freight fills Big 10 Curve nicely approaching Rocky, Colorado, on Valentine’s Day 2015 afternoon. Seven locomotives are up front, beginning with EMD SD70ACe No. 8559... (more)

Rounding Big 10 Curve west of Rocky, Colorado, is Union Pacific freight MRONY (Roper to North Yard manifest) on February 14, 2015. The eclectic motive power consist includes EMD SD70ACe No. 8559, ... (more)

Early morning sunlight glints off portions of Union Pacific’s CEYPS unit coal train slinking through Rocky, Colorado, on February 9, 2015. UP SD70ACe No. 8888 and GE AC4400CW No. 5609 lead the t... (more)

With the main line clear of traffic, Union Pacific’s West Local drops off the grade on Rocky Spur (now known as Rocky Flats Industrial Lead) and enters the main at Rocky, Colorado, on the aftern... (more)

Union Pacific’s Denver to Salt Lake City manifest freight MNYRO climbs the two-percent grade through Barbara Gulch into Rocky, Colorado, on February 2, 2014. Four GE AC4400CWs power the freight,... (more)

Union Pacific’s Salt Lake City to Denver (MRONY) freight rounds Big 10 Curve west of Rocky, Colorado, on June 9, 2013. Far below on the edge of the Great Plains sits the sprawling city of Denver... (more)

An eastbound BNSF coal train descends the Front Range of the Rockies at Big 10 Curve west of Rocky, Colorado, on May 5, 2014. Three brand-new EMD SD70ACes lead the train (Nos. 8533, 8531 and 8530)... (more)

A westbound BNSF manifest freight climbs “Little 10 Curve” at Rocky, Colorado, on the afternoon of June 9, 2014. Leading the train is repainted GE C44-9W No. 4490, followed by AC4400CW No. 583... (more)

Amtrak’s “Phase I Heritage” locomotive, GE P42DC No. 156, leads the eastbound California Zephyr down the Front Range of the Rockies west of Rocky, Colorado, on the afternoon of June 1, 2014.... (more)

The Rio Grande Ski Train climbs the 2-percent grade between Rocky and Clay, Colorado, on June 30, 2007. Three former Amtrak F40PHs power the westbound train, which is a “summer edition” of the... (more)

Union Pacific’s West Local traverses the Rocky Spur above an eastbound coal train tied down in the siding at Rocky, Colorado, on January 27, 1998. Power for the local is Rio Grande GP30 No. 3003... (more)

Two Rio Grande GP30s power Union Pacific’s West Local on the Rocky Spur above Rocky, Colorado, on October 23, 1997.

Approaching Big 10 Curve is Amtrak No. 5, the westbound California Zephyr, west of Rocky, Colorado, on October 11, 1999. Powering the train are GE P42DC Nos. 30 and 67, with EMD F40PH No. 259 thro... (more)

Union Pacific’s MRONY freight drops off of the mesa at on Big 10 Curve west of Rocky, Colorado, on June 28, 2014. Today’s train is fairly short, with the lone DPU locomotive visible on the opp... (more)

At 5:58 a.m. on June 4, 2014, a westbound BNSF manifest freight climbs through Rocky, Colorado, on Union Pacific’s Moffat Tunnel Subdivision.