“Bite-Size Bits of Local, National, and Global History”
“Bite-Size Bits of Local, National, and Global History”
Georgetown in Clear Creek County, Colorado — The American Mountains (Southwest)

The Story of the Eisenhower-Johnson Memorial Tunnels

We went by the book, but the mountain couldn't read

— R.C. (Rube) Hopper, 1972 —

The Story of the Eisenhower-Johnson Memorial Tunnels Marker image. Click for full size.
Photographed By Duane and Tracy Marsteller, July 4, 2020
1. The Story of the Eisenhower-Johnson Memorial Tunnels Marker
Inscription.  Colorado's scenic wonders lured settlers and tourists alike. Geography and weather placed strict limits on travel routes and seasons. Politicians, engineers, and citizens often disagreed about how to cross the Continental Divide. Between 1941 and 1943, the Department of Highways constructed the "Pioneer Bore," the first attempted construction of a high-altitude tunnel near Loveland Pass. The 7'x7' tunnel was just over a mile long. The route was eventually abandoned as road standards changed after 1945.

In the 1950s, the Western Slope agricultural community needed reliable, year-round routes to Denver markets and railroads, while Colorado's booming tourism industry demanded improved highways. The 1956 Interstate Highway Act provided federal funding to answer these challenges. The route along Straight Creek, today's westbound Eisenhower tunnel bore, was deemed the best of eight possible routes, but construction would not begin for another decade.

Despite occasional snow flurries, and temperatures in the mid-30s, Colorado Governor John A. Love dedicated the Eisenhower Tunnel on March 8, 1973. He proclaimed the tunnel to be "the
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most effective answer to tying east and west Colorado together and opening the way West." The tunnel, open in all weather, saved motorists 9.1 miles of the slow, winding road over Loveland Pass.

Before the first tunnel opened, the Department's engineers were designing the second bore. The Eisenhower Tunnel accommodated both east and west bound traffic and the Department knew that was not a long-term solution. Excavation of today's eastbound Johnson Tunnel began in 1975. Completed and dedicated on December 21, 1979, this second tunnel was named for Colorado Governor and U.S. Senator Edwin C. Johnson.

[Left column:] People
Rules for the road
An avid sportsman, Dwight Eisenhower started visiting Colorado shortly after World War II. Like the average citizen, "Ike" occasionally found himself caught in traffic on U.S. Highway 40 between Fraser and Denver. As president, he signed the Federal Interstate Highway Act of 1956. The Colorado state legislature memorialized him by naming the Straight Creek Tunnel, today's westbound bore, the Eisenhower Memorial Tunnel in 1972.
The observant engineer
From survey crew to executive director, Charles Shumate spent five decades (1924-1975) employed by the Colorado Department of Highways. Shumate was an engineer's engineer and a newspaper reporter's dream as he was always good for a
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quote. In 1963, as work began on the bore beneath the Continental Divide, Shumate pronounced the work "the most difficult feat ever undertaken by the Colorado Highway Department."
A new light at the tunnel
A Department of Highways clerical error offered Janet Bonnema a tunnel engineering job in 1970, transforming the Department's workplace culture. In 1972, a state constitutional amendment guaranteed equal rights for women, superseding miners' superstitions about women underground. Eighteen months after she was hired, engineer Janet Bonnema went underground to perform her duties, prompting a walkout of about 60 workers. All but one man returned the next day.
Phillip McOllough, project engineer
Phillip McOllough was the Department of Highways' tunnel construction engineer, and later district engineer, for both the Eisenhower and Johnson bores. From July 1968 until the Johnson tunnel opened in 1979, McOllough helped create and implement new construction techniques when the workers encountered "bad rock". His cautious work saved lives and brought both tunnels to a successful completion. He was district engineer until 1981.
The tunnel's guiding light
R. C. (Rube) Hopper served as the tunnel's district engineer during the Eisenhower bore's construction. Hopper oversaw the drilling of multiple small tunnels, or drifts, in an arch pattern and backfilled with concrete. The drifts provided necessary support to keep the mountain's "bad rock" from crashing down on workers and equipment. Reflecting on construction, Hopper joked: "We were going by the book, but the mountain couldn't read."
Big Ed
Edwin C. "Big Ed" Johnson fought to bring an interstate highway to the Rockies. Serving three terms as U.S. Senator and two terms as Governor, Johnson used his political savvy to convince the federal government to route the interstate through Colorado. Johnson's efforts broke the decades-long stalemate over high country road construction. The state named the eastbound bore in his memory in 1979.

[Right column]Challenges
How to open a mountain
Challenges of tunnel construction at 11,000 feet included reduced efficiency of workers and equipment and a shorter construction season. After careful planning and a pioneer bore, engineers could not predict all rock conditions. In 1967, the winning bid was $54 million to open the Eisenhower bore. The final cost topped over $100 million. Rechanging the tunneling method due to bad rock conditions doubled the cost.
Time is money
It took less time, but it wasn't less expensive the second time around. The Eisenhower bore was still under construction when the state opened bids for the Johnson bore. The Johnson bore's final cost topped approximately $100 million. Engineers estimate that if these tunnels were built in the early 21st century they would cost around $1.5 billion.
Mining a tunnel
Excavation comprised four tasks — drilling, loading, shooting and mucking. Holes were drilled around the rock the miners wanted to remove. Explosives were then loaded into these holes and "shot," or blasted. After each blast, miners and front-end loaders mucked out loose rock and dumped it into narrow-gauge mining cars pulled by an electric locomotive. The Department ultimately used the loose rock in road construction.
Cold, noisy and dark: Life inside the mountain
Eight hours of sensory overload may be the best way to describe a shift in the Eisenhower and Johnson bores. The Denver Post described conditions inside the mountain as "sound becomes a physical torrent," water "leaks" from the rocks and miners wore "grimy, rubber-coated tub overalls." At construction's peak, 1,140 people worked three shifts 24 hours a day for six days a week.


Before the Tunnels

In the 1960s, Charles Shumate witnessed "50 to 75 cars going around and around the capitol building honking their horns and with signs saying, 'The Western Slope Needs to Tunnel Under the Continental Divide'." The completed tunnels linked eastern and western Colorado with a year-round reliable route. Approximately 310 million vehicles drove the tunnels from the late 1970s to the early 21st century.
The tunnels today
The Eisenhower-Johnson Memorial Tunnels are the largest structures built with Interstate funds and stand at an elevation of 11,158 feet, the highest on the Interstate system. Construction took 13 years and $220 million to mine the tunnels, build the ventilation buildings, and the highway approaches to the tunnels.

A staff of approximately 50 persons perform critical operations and maintenance duties at the tunnels at every hour of every day to keep traffic moving across Colorado. Every day, workers watch for and immediately respond to vehicle breakdowns or other problems that might slow down or stop traffic, or lead to more serious accidents. In fact, there has never been a fatal accident in the tunnels in 40+ years of operation.

We knew there was bad rock in there
: By 1969, all involved in construction faced a dilemma. They knew that the mountain still moved along the Loveland Fault and fragile rock could come crashing down at any time. Designed to dig and hold up the rock simultaneously, a 450-ton mining shield moved only a few yards before a combination of loose rock and pressure unintentionally seized the shield in its tracks.
Technique: The builders opted for the multiple drilling method. Crews dug 13 small tunnels, or drifts, six to eight feet tall, to form an arch. Workers filled each drift with concrete. The drifts were dug starting at the bottom of the arch so the concrete at the top of the first drift served as the second drift's floor.
Result: The multiple drilling method prevented further cave-ins and allowed subsequent excavation of the mountain's middle where crews expanded the tunnel . Tunnel engineer R.C. (Rube) Hopper observed that multiple drilling was "a little slow, but it is foolproof."

1879 William Loveland builds a wagon road over the mountain pass named later in his honor
1929 First automobile crosses Loveland Pass
1938 Colorado completes US Highway 40 over Berthoud Pass
1941 The Colorado Department of Highways begins the first, or pioneer, bore under Loveland Pass
1943 Department of Highways advertised for bids to tunnel under Loveland Pass but all bids come in over the $10 million the department anticipated
1950 The State Highway Department paves U.S. Highway 6 over Loveland Pass
1963 Contractors begin pioneer bore of the westbound Straight Creek Tunnel
1964 First 2.6-mile section of I-70 opens from Floyd Hill to Idaho Springs
1967 Straight Creek Constructors submit the winning low bid of $54.1 million for the first tunnel
1973 Eisenhower Tunnel opens on March 8, 1973
1975 Colorado Department of Highways approves low bid of $102.8 million for the second bore, later named the Johnson Tunnel
1979 The Johnson Tunnel opens for eastbound traffic
1984 The Department of Highways completes the last segment of I-70 through Glenwood Canyon

Left side, clockwise from top left
• President Dwight D. Eisenhower and Colorado Governor Ed Johnson in the Oval Office, about 1953
• Janet Bonnema laughing with R.C. (Rube) Hopper on her first trip into the tunnel, 1972
• Former Colorado Governor and Senator, "Big Ed" Johnson, center, with unidentified men at the tunnel worksite, early 1960s
Photo taken by the Colorado State Patrol. Courtesy of the Denver Public Library, Western History Collection. Unnumbered.
• The Eisenhower bore's opening on March 8, 1973. From left to right, R.C. (Rube) Hopper, Colorado First Lady Ann Love, Charles Shumate and Red Gillette.
• An ecstatic Phil Mcollough, Department of Highways District Engineer, is surrounded by contractors from Peter Kiewit & Sons. Dozens of state employees and hundreds of contractors worked for over 10 years constructing the Eisenhower and Johnson bores. It took another 16 months after the "hole-through," shown in this picture, before the Johnson bore opened to traffic.
Front: Rod Nickerson, Phil McOllough, and Bill Roberts; Center: Marv Bishop, L.D. Bowerman, and Ray Poulsen; Back: Joe Jaudon. 8/17/1978

Right side, clockwise from top left
• The simple act of walking required extra [indecipherable] "This mountain leaks. If the pedestrian watches where he is putting his feet he finds cold water running down his neck." — The Denver Post, 1978.
• Miners preparing charges for a blast, 1977.
• [indecipherable]
• Opening Day 1973: Two-way traffic flowed in the Eisenhower bore until the Johnson bore opened in 1979.
• Workers construct a drill jumbo for the next segment of tunneling, 1977
Erected by Colorado State Historical Fund, U.S. Forest Service and Colorado Department of Transportation.
Topics and series. This historical marker is listed in this topic list: Roads & Vehicles. In addition, it is included in the Former U.S. Presidents: #34 Dwight D. Eisenhower series list. A significant historical date for this entry is March 8, 1973.
Location. 39° 42.893′ N, 105° 41.74′ W. Marker is in Georgetown, Colorado, in Clear Creek County. Marker can be reached from Argentine Street. Marker is located near entrance to visitor center. Touch for map. Marker is at or near this postal address: 1491 Argentine Street, Georgetown CO 80444, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Masonic Temple, 1892 (approx. 0.6 miles away); Fish Block, 1889 (approx. 0.6 miles away); Monti and Guanella Building, 1867 (approx. 0.6 miles away); Cushman Block I, 1872 (approx. 0.6 miles away); Old County Courthouse, 1868 (approx. 0.6 miles away); Cushman Block II, 1872/1875 (approx. 0.6 miles away); John Tomay Memorial Library 1924 (approx. 0.6 miles away); Kneisel and Anderson Store, 1892 (approx. 0.6 miles away). Touch for a list and map of all markers in Georgetown.
Credits. This page was last revised on July 15, 2020. It was originally submitted on July 14, 2020, by Duane and Tracy Marsteller of Murfreesboro, Tennessee. This page has been viewed 1,044 times since then and 376 times this year. Photo   1. submitted on July 14, 2020, by Duane and Tracy Marsteller of Murfreesboro, Tennessee. • Andrew Ruppenstein was the editor who published this page.

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Jun. 9, 2023