For railroad buffs there is no better place than the Colorado Front Range mountains with tracks winding through picturesque valleys and 20 tunnels through solid rock. Union Pacific, BNSF, Amtrack and the Santa Fe lines share the tracks as they haul freight, coal and travelers between Denver's Union Station and the west coast.
Beautiful Union Station in downtown Denver is the railway hub of Rocky Mountain west. From there the trains head west through Denver towards the Front Range foothills. The cities and suburbs offer dozens of excellent vantage points for train viewing. When train watching always remember to respect the boundaries of the train engineer. The engineers are responsible for the safety of their trains and don't need the extra headache of worrying about over zealous train enthusiasts standing on or near the tracks. I recommend a vantage point at least 30 yards from the tracks, safe for the viewer and distant enough to keep the engineer from being nervous about your safety as well.
Tunnel #1 is one of the first places in the foothills to catch a view of the massive steel snakes as they make their journeys to and from the great American West. To reach the the tunnel take Highway 93 north out of Golden to Highway 72 and head west. On the north side of the road look for the first huge knoll which is the formation that the tunnel passes through. Hike through the meadow to the north to see the north side of the tunnel or up the steep embankment to view the south entrance. Generally the wait shouldn't be more than a half hour to an hour before a train comes through.
Tunnel #2 is on Plainview road, a dirt road that heads north from Highway 72 just east of Tunnel #1. The road is unpaved but easily passable with a passenger car. Proceed along the road and find a place to park when you come to the tracks. The tunnel is north of there and can be approached on foot by hiking north at a safe distance along the tracks. Watch locomotives proceeding in and out of the tunnel against the beautiful backdrop of the Boulder Flatirons.
The tracks then proceed into the foothills through El Dorado Canyon State Park with Tunnel #10 being accessible from the Rattlesnake Gulch Trail. El Dorado Canyon is one of the most beautiful places this writer has ever come across. I have done a lot of hiking and climbing there but have never made the climb to Tunnel #10, which remains on my train watching bucket list. I have seen the view from an Amtrack train and can only imagine the vistas available on all the twists and turns of the footpath.
Another great place for train viewing is on Gross Reservoir Road near the town of Coal Creek on Highway 72. Follow Gross Reservoir Road to the tracks and find a suitable parking spot. Tunnel #19 can be found by hiking west along the tracks for a half mile or so, while Tunnel #18 can be viewed by hiking east. Fantastic views of the trains and the peaks of the Colorado Continental Divide to the west can be experienced by climbing to the top of the bluffs east of the road and north of the tracks. Trains can be viewed breaking through the foothills from El Dorado Canyon as you look to the east. Extensive hiking is required to view tunnels 11-17, but well worth the effort for the serious tunnel buff.
The little mountain town of Pinecliffe further west on Highway 72 is the next good viewing location. From there you can hike east along the tracks across a little bridge to view Tunnel #29 and the massive cliff above. This is a nice place to visit when the aspen trees are clothed in their golden autumn glory.
Mountain wilderness limits accessibility to the tracks between Pinecliffe and Rollinsville but Rollins Pass offers some of the most spectacular train viewing imaginable with beautiful mountain scenery, trestles, bridges and the crown glory of the Eastern Slopes, the Moffat Tunnel. Built between 1922 and 1928, the Moffat Tunnel cuts 6.5 miles through the solid rock of the mountains of the Indian Peaks Wilderness and the Colorado Continental Divide. The tracks and road leading to the tunnel entrance offer wonderful nostalgic photo opportunities and a journey into American history. Rollins Pass Road is a rough ride but well worth the trouble. The engraved concrete Moffat Tunnel entrance set against the massive mountains of the Indian Peaks Wilderness is quite picturesque and the railroad activity there fascinating to watch. For the more adventurous, a hike to Crater Lakes in the high peaks behind the tunnel is worth the climb.