The Hagerman Tunnel can be approached from either end but only close enough to peek inside. On the west side, a small opening at the top of the tunnel can be used to view the construction of the ceiling and walls but a battery operated spotlight will be needed.
The east side was carved from solid rock so beams were not required to support the ceiling or walls. For most of the year, the water inside is frozen.
Getting from one side to the other is accomplished by crossing Hagerman Pass at 11,925 feet. Snow is normally melted off the pass in late July or August. A passenger car road accesses the east portal of the Carlton Tunnel. From that point on, the road becomes somewhat rougher. It should be done in a high clearance vehicle due to rocky sections that will damage the undercarriage if mistakes are made.
On the west side, a well maintained road leads to the maintenance headquarters at the Carlton Tunnel. At the entrance to that complex, turn left on the steep rocky path going around the back of it. From there, the narrow road uses the original railroad grade all the way to the tunnel. It is a scenic drive with a few small camp sites.
Navigation
This route follows county roads to the west side of Hagerman Tunnel then crosses the pass to the east side. Take exit 147 off I-70 for Eagle, Colorado. Go south through the traffic light, under the overpass, and turn right at the circle drive. Go one block and turn left on Capitol St. Follow Capitol St. and reset your trip meter when it crosses Sixth. Also reset your trip meter any time you see 0 in the trip meter column.
 The view from the Hagerman...  The view from the Hagerman Pass Road offers a good view of the valley. If the water level is low in Ivanhoe Lake, the old railroad grade can be seen poking through to the surface. |  On the east side of Hagerman...  On the east side of Hagerman Pass, the road offers some good views of the railroad grade that once carried trains in and out of the Hagerman Tunnel. |  Except for a few rocky areas,...  Except for a few rocky areas, the road over Hagerman Pass to the Carlton Tunnel is easy to navigate. Along the way, it passes a parking area for the hike to the Hagerman Tunnel. |
 The water diversion maintenance...  The water diversion maintenance headquarters sits near the mouth of the Carlton Tunnel west portal. The track from there ran down the valley across the land now flooded by Ivanhoe Lake. The road to Hagerman Tunnel passes behind the maintenance headquarters. The Carlton Tunnel is part of a project that pipes water from the western slope of the Continental Divide to the eastern plains where most of the population resides in Colorado's major cities. |  The old railroad grade providing...  The old railroad grade providing access to the west end of Hagerman Tunnel is narrow and very scenic. The road ends at the west portal for the tunnel. It is possible to see inside using a high power spotlight. |  The road over Hagerman Pass...  The road over Hagerman Pass tops out at 11,925 feet. It is a good road but rocky in places. The tires on Lone Writer's vehicle are provided by BFGoodrich. |