Tunnel City (CP Rail)

The main viewing point is the grade crossing on WI-21, reached by heading 3.5 miles west from I-94 Exit 143 near Tomah. From the crossing you have a clear sight line into the tunnel's east portal and along the track eastward toward Tomah. Westbound trains disappear into the bore at reduced speed; eastbound trains emerge with dynamic brakes working loudly as they crest the summit grade, then throttle up for the run downhill toward Tomah. Train lengths regularly exceed 8,000 feet, and distributed-power units mid-train or at the rear are common on unit grain and potash trains, making for a long procession past the portal.

The collapsed ruins of the 1910 CNW tunnel (which caved in March 1973) are visible in the brush on the adjacent hillside, adding a layer of railroad archaeology to the visit alongside the live action. The combination of steep-grade drama, tunnel emergence, and a public road crossing all within a few hundred feet makes this one of the more memorable action spots in the upper Midwest.

Tunnel City sits at roughly 950 feet elevation where sandstone bluffs rise sharply from the rolling dairy farmland of Monroe County. Mixed oak and maple forests cloak the slopes above the portal, providing lush summer green and vivid autumn color from mid-October through early November. Winter strips the canopy and opens longer sight lines through bare trees, while morning fog often settles in the valley east of town, occasionally framing locomotives emerging from the bore against low cloud. The hamlet itself is minimal — a handful of houses, a small church, and Holstein dairy pastures on either side of WI-21 — which keeps the rail action the center of any visit.

CPKC's Tomah Subdivision is a primary corridor linking Chicago, the Twin Cities, and western Canada, carrying mixed manifest, grain, potash, ethanol, and intermodal traffic. Union Pacific also has trackage rights over CPKC from Tunnel City west to Winona, Minnesota — an arrangement dating from the March 1973 collapse of the parallel CNW tunnel — so UP manifest and intermodal trains pass through on CPKC iron alongside CPKC power.

Two Amtrak services use the line and stop at Tomah station (8 miles east) but pass through Tunnel City without stopping: the Empire Builder (trains 7 and 8, Chicago to Seattle/Portland, daily) and the Borealis (trains 1333 and 1340, Chicago to St. Paul, daily since May 2024). At Tomah, the Empire Builder is scheduled at approximately 11:26 AM eastbound and 6:27 PM westbound; the Borealis at approximately 2:17 PM eastbound and 2:43 PM westbound. Allow 15–20 minutes of travel time between Tomah and Tunnel City when timing a visit around Amtrak.

The grade crossing on WI-21 provides the most accessible vantage. Position on the south side for head-on shots of eastbound trains emerging from the tunnel portal; morning sun from mid-morning onward front-lights locomotive noses. For westbound trains entering the portal, afternoon light from the west is preferable. A telephoto lens in the 200–400mm range isolates the portal within the forest canopy framing. Train speeds through the area are relatively low on the westbound grade, giving ample time to track the consist. Elevated vantage points above the track on the bluffside require a short hike on uneven terrain but offer broadside views showing longer trains against the forested hillside. The visible ruins of the 1910 CNW portal in the adjacent hillside provide a photogenic historical counterpoint in wide-angle compositions.

Tunnel City takes its name from a tunnel completed in 1858 by the La Crosse and Milwaukee Railroad, which needed to pierce the north-south ridge separating the Mississippi and Wisconsin river watersheds to complete its Milwaukee-to-La Crosse line. Before the tunnel opened, oxen-powered pulley systems were used to drag cars over the hill — a three-year arrangement that underscored the engineering importance of the bore. The original tunnel collapsed in 1875 and Milwaukee Road dug a replacement directly to the north, which remains the active CPKC tunnel today; its floor was later lowered in the 1960s to accommodate taller equipment.

A third tunnel through the same hill was driven in 1910 by the Milwaukee, Sparta, and Northwestern Railroad (a Chicago and North Western subsidiary) for its Adams Cutoff. That bore was the only double-track-width tunnel on the CNW system, though only a single track was ever laid through it. It collapsed in March 1973 after several days of heavy rain saturated the sandstone bluff. Union Pacific — which had absorbed CNW — subsequently received trackage rights over the adjacent CP line from Tunnel City to Winona, Minnesota, an arrangement still in effect today. The ruins of the 1910 portal remain visible in the hillside, and the active CPKC line traces continuous rail operations at this location back to 1858.

Tunnel City is the site of Wisconsin's only active railroad tunnel, together with the visible ruins of a second collapsed bore from 1910 — a combination that makes it simultaneously a working operations spot and a site of railroad archaeology. The junction adds operational variety: both CPKC and Union Pacific trains use the same track through the tunnel, offering two Class I railroads in a single session. Because the grade crossing on WI-21 is public and close to the portal, productive photography requires no trespassing and minimal hiking. Few spots in the upper Midwest combine a working tunnel, a multi-railroad junction, daily Amtrak service, and easy public access in one location.