the eisenhower memorial tunnel about 60 miles west of denver on interstate 70 sits at 11 0013 feet at
the east portal and 11 158 feet at the west portal the tunnel traverses through the continental
divide at an average elevation of 11 112 feet when initially opened in the 1970s the tunnel was
not only the highest vehicle tunnel in the u.s but it was also the highest in the world this facility
lies entirely within the arapahoe national forest and is divided by two counties clear
creek county at the east portal and summit county at the west portal the tunnel and the continental
divide also separates two watersheds the clear creek watershed on the east and the straight
creek watershed to the west and it's these unusual elements that make the eisenhower tunnel projects
one of the most ambitious undertakings of colorado's history so join me as we discover
the highest vehicle tunnel in america i'm your host ryan socash and you're watching it's history
before the construction of the tunnels and interstate 70 vehicles crossed the
continental divide by driving over loveland pass 11 922 feet on highway
6 a winding two-laned highway that could take more than an hour to navigate in 1956
president dwight d eisenhower signed the federal aid highway act which authorized the federally
funded construction of an interstate highway system in the united states
the original highway planners had no intention of constructing an interstate through the formidable
colorado rockies which many believed would be too expensive and too complicated however colorado
governor edwin c or big ed johnson and members of the state's congressional delegation lobbied
federal officials to extend interstate 70 through the rocky mountains johnson and his supporters
argued that the interstate would pay for itself through increased commerce especially money
from tourists so eventually the federal government agreed to extend the interstate through colorado
and pay 90 percent of the construction costs the state was responsible for the remaining 10 percent
construction on the tunnels beneath the continental divide proved difficult expensive
and dangerous digging on the first tunnel started in march of 1968 intended to open in three years
however the engineers and construction workers quickly discovered that the project would be
more complex than initially planned harsh winters made for short work years outside the tunnel not
to mention the men and equipment did not work well at the high altitude inside the tunnel miners
discovered weak rock layers the engineers had not anticipated and the mountain could not support
itself once certain sections had been dug through with ingenuity however the crews devised a way to
bore through the tunnel without triggering a collapse and the tunnel continued to inch
deeper into the mountain geological studies showed that bedrock in the tunnel area consists
of 75 percent granite 25 percent nice and chist there are faults and sheer zones as well as solid
bedrock in the pilot board 26.5 of its length was in a self-supporting rock 73.5 required supports
in varying degrees and the total footage of what tunnelers called bad rock was 820 feet because the
location was the westbound board lines between 115 and 230 feet to the north rock conditions did not
precisely duplicate those of the pilot tunnel the westbound tunnel generally runs east and west and
curves midway into the mountain the twin tunnel's second or eastbound bore was later constructed
in a more or less straight line center line to centerline the twin tunnels are 115 feet apart
at the east ventilation building entrance 120 at the west ventilation building entrance and some
230 feet at the widest point of separation under the mountain now in addition to the
grueling conditions of construction there were also some very unusual events that unfolded on
friday october the 2nd 1970 during the tunnel construction workers constructing the tunnel
were among the first on the scene of a plane crash that had occurred less than two miles northeast
of the east portal one of two charter aircraft carrying a college football team crashed
just north of the highway of the 40 passengers and crew on board only nine survived the team was on
its way to a game the plane carrying the team's starters departed denver and traveled a poorly
planned scenic route the other plane carrying reserve players followed the original path
and landed safely among the project's large workforce janet bonima deserves special
attention you see the colorado highway department mistakenly hired her a highway engineer with a
degree from the university of colorado because they believed they were hiring a well-qualified
mr bonima anyhow when miss bonama arrived on the job she was not allowed to enter the tunnels even
though it was her job to do so as an engineering technician she was kept outside the tunnels and
at a desk because construction workers believed having a woman in the tunnels would jinx the work
site this taboo concern was so widely accepted that on the day bonama finally entered the tunnels
surrounded by reporters most of the work crew actually walked out of the tunnel
some of whom never returned to their job the majority of the staff however returned to work the
next day and miss bonama continued to work in the tunnels often dressed in loosely fitting coveralls
so no one could tell her identity apparently many tunnel workers opposed women working on the site
stating a superstition that having females on site was terrible luck as it turns out miss bonama was
encouraged by an equity law recently passed in the state so she filed a lawsuit against the colorado
department of transportation and actually won after five years of construction the first tunnel
opened for highway traffic on march the 8th 1973 the eastbound tunnel opened for traffic six years
later on december the 21st 1979 when it opened the eisenhower johnson memorial tunnel was the
highest mountain tunnel in the world it should be noted that several train tunnels in asia have
since surpassed it but it does remain the highest vehicle tunnel in the world and the highest point
in the u.s interstate highway system ultimately this project went far over budget totaling more
than 257 million by the time both tunnels were finished with historians pointing out that this
amount was equal to the original estimate of the entire stretch of interstate 70 from denver to the
utah state line more than 1 000 men and women worked six days a week year round to complete
the tunnels despite safety precautions three people lost their lives constructing the first
bore of the tunnel and four on the second many others suffered amputations surgeries and various
other work-related injuries however compared to the roadways of the past the tunnels themselves
are phenomenally safe not a single death in 40 years of operation this is partly because the
facility and its staff are evolving to keep pace with increased traffic demand and vehicle risks
for example the tunnels have their own war room where staff monitors toxic gas and car exhausts
like carbon monoxide which is crucial as these gases can accumulate quickly within a tunnel
therefore tunnel air is circulated through ducks stashed above the road these ducks are nearly as
tall and wide as the road itself on opening day a ceremony was held inside the tunnel's east portal
in freezing conditions with occasional flurries members of the eisenhower family had been invited
but did not attend governor love called the tunnel quote a tremendous accomplishment for colorado but
you'll never believe what happened to the first person who drove through the tunnel you see they
received a summons for trespassing the historic moment occurred in late 1972 when a driver who had
been drinking decided that he not governor love should have the honor of being the first person to
drive through the tunnel so he zoomed past a sign that prohibited traffic and then passed through a
foot deep of mining muck or mud when he emerged his car was covered in silt the judge dismissed
the charge because the signs prohibiting traffic at the tunnel entrance weren't adequate now from
the outside face to face the ventilation buildings stand at a distance of 8941 feet from one another
of this distance there are 7 789 feet of rock tunneling 1152 feet of ventilation slash portal
structures and cut and cover sections at the east and west ends meaning that there is far
more to these tunnels or complex even than meets the eye in fact while the eisenhower tunnel was
primarily intended as a transportation tunnel it also served as a water tunnel for water diversions
from the western side of the continental divide to the eastern side water from the
straight creek watershed and the seepage entering the tunnel is discharged into clear creek for use
by a local brewing company typically the tunnel delivers over 300 acre feet of water per year
the tunnels are complex to run in the multi-story portals on both ends of the tunnel
about 40 employees who work shifts at all hours run utilities that include the ventilation
system a waste water treatment plant and minor electrical substations this of course is to power
the 28 gargantuan intake and exhaust fans in the control room which has a mix of modern and let's
say apollo era equipment employees monitor live video feeds of the tunnels and crucial points
along the i-70 mountain corridor for any trouble the fire crews stand by and are ready to respond
in any emergency situation these firefighters have been aided by a 22 million dollar in-tunnel fire
suspension system installed back in 2015 basically adding sprinklers the giant fans also help clear
the air quickly during a tunnel fire the tunnel is staffed 24 hours a day 365 days a year
to provide a safe and adequate service to the motoring public now believe it or not at one time
a tram car was suspended from the wall this was a gasoline-powered unit that could travel through
the length of the tunnel carrying an attendant an emergency power system is also in place to use as
an emergency backup in case the commercial source of electricity is ever interrupted now although
the eisenhower tunnel has modern equipment the old systems are beginning to decline from wear
and tear just as the building of the eisenhower tunnel required ingenuity cdot now faces a modern
challenge 48 years after the first tunnel bore opened some emerging repairs are needed including
replacing the leaky main water lines beneath the roadways pavement which will most certainly
require a creative if not expensive solution beyond that there are three places of particular
concern where groundwater is seeping through the porous concrete membrane that lines the tunnel
pipes are set up on the wall to funnel the water into a drainage system but it sometimes pools and
freezes in the corridor or perhaps even more concerning is that some water actually flows down
into the vehicle tunnels staining the wall panels to the point that it's pushed some panels outwards
by several inches during freezing conditions luckily one near-term project on the repair list
calls for injecting grout to fill voids into the fractured rock and soil around the tunnel
it's also agreed to build a bike path along the interstate pass the work and sacrifice of
these men and women made commuting from the front range to the western slope much more accessible
and helped increase access to the high country a drive through the tunnels from one side of the
continental divide takes about five minutes while a trip over loveland pass can still take more than
an hour this shorter and much safer commute has strengthened commercial ties it's boosted the
economy of many mountain towns and just beckons skiers snowboarders and anyone wishing to visit or
live in the colorado rocky mountains and i think this is a beautiful notion as tourism was upon one
of the official justifications of building what was once the highest tunnel in the world now if
you love tunnels i've got great news for you as we have an entire playlist dedicated to that topic
and for our channel members those of you who generously clicked join i just visited the
longest narrow gauge train tunnel in all of europe and with that this is ryan socas signing off