The Glasgow courier. [volume] (Glasgow, Mont.) 1913-current, 1920-07-23
ENGINEERS CHECK
MOVING

When an entire mountain becomes
dissatisfied with it's location and be-
gins to slide, it means trouble for
whatever happens to be in the way.
Anyone who has noticed how even a
small slide sweeps everything before
it, appreciates the force in a moving
mass of earth. When the slide in
cludes. a mountain, instead of simply
a loose portion of it's surface, the
movement may be said to be irresist-
able. If stopped at all, it must be at
tackled by engineering strategy, for no
force will prevail against it.
In a commanding position on the
Oregon side of the Columbia river,
between Cascade locks and Eagle
creek, about as miles from Portland,
stands the Moving Mountain" Altho
for the past year there has been no
movement, and engineers are hoping
they have succeeded, in a fight they
have made through several decades,
in staying its progress, they are not
ready to say that the mountain is con-
quered. To the layman, however, it
looks very much as though the noun
tain had come out second best in it's
struggle to glide into the waters of
the Columbia, and that, from now on,
it will remain %steadfast in it's pres
ent location, as a well-behaved noun
tain should.
There has at no time been anything
very precipitate about the movement
of this Columbia river peak. It-might
have gone on indefinitely without at
tracing attention, if it had not been
for the construction of a railroad at
it's base back in 1880. The engineers
who surveyed the line were greatly
surprised to notice, after several
months, that some action had affect
ed their location stakes. The change
was slight, but sufficient to arouse
curiosity and apprehension. Definite
observations were made from month
to month, and from these it was de-
termined that the land at this place
was sliding toward the Columbia at
the rate Of 10 to Is feet a year. At
first, it was thought that the disturb
ance might be confined to a very
small and localized area. Experiments
quickly proved this premise wrong,
however.
The Moving Mountain itself bord-
ers the river for three-quarters of a
mile. It's face is a series of serrations
and there are several areas that have
no surface outlet. Water gathering in
these undrained basins seeps through
the soil, reaching bedrock at a level
somewhat below the surface of the
river. To this drainage water is adj
ded seepage from the river, which
flows in over the bedrock where it is
exposed along the bank. AS a re-
suit, the mountain rests on a thin film
of water that covers the bedrock I'M
der it's entire base. The tremendous
weight on this thoroughly fabricated
surface causes the movement.
Until recently, surface drainage was
depended on to stop this. Efforts
were made to drain the low areas, for
it was reasoned that if the water did
not permeate the mountain, the slide
would stop. Surface drainage, how
ever, proved a failure.
The new plan of attack, which has
stopped the slide, at least Temporal
lily, consists of a series of drainage
tunnels. These were built in 1918.
The portals of the tunnels are at about
normal high-water level of the river,
and have a depth of so feet. When
the tunnels had penetrated the noun
tain for some distance drifts were dug
at right angles to reach the most ad-
~vantageous locations.
The tunnels have offered drainage
for the film of water that covered the
bedrock surface, and a large volume
of water has been concentrated in
them. AS oon as the tunnels were
completed, last year, the slide move
ment ended and has not, so far, re-
Cured.
The famous Columbia River high
way now parallels the railroad at the
base of the Moving Mountain. II
had been built only a short time be-
fore the slide was stopped and was not
affected. If the movement should be-
gin again, frequent changes of the
highway, as we'll as the railroad
would be necessary. However, this is
a contingency that is not anticipated
for it is generally believed that the
tunnels have solved the difficulty
ACKNOWLEDGEMENTS Mechanics.