INTERDISCIPLINARY TEAM FIELD TRIP
APRIL 21, 1987
Jim Naegle, UDOT
John Neil, UDOT
Howard Richardson, UDOT
Lynn Zollinger, UDOT
Fred LaBar, USFS
Mark Shaw, USFS
Richard Harris, USFS
Clark Ostergaard, USFS
Duncan Silver FHWA
Stan Nuffer, CH2M HILL
Cliff Forsgren, CH2M HILL
Arlo Waddups, Valley Engineers
Jack Spence, Sierra Club
Steve Flint, Audubon
The team met at 8:00 a.m. at the Forest Service District
Ranger's office. Transportation for the field trip was in
two vans provided by UDOT. Weather conditions for the trip
The primary purpose of the trip was to get an idea of the
magnitude of the changes that would be required for Alternates
C and D. Some spot improvement locations (slow vehicle turnouts)
were observed but generally the "no action" and "spot
improvement" alternatives were not the subject of this trip.
Stop No.1 was at Lower Canyon M.P • . 382.8 to consider the
possibility of a slow vehicle turnout prior to the beginning
of the study area. A slow vehicle turnout in this location
would be marginal due to the curvature in the roadway and
the limited sight distance back along the roadway.
Stop No.2 was at M.P. 384.0, or curve No.5 which is the
first sharp curve encountered in the study section. Valley
Engineering had previously marked the location of the centerline
and the limit of the cut for both a 35 and 40 mph design.
Red and white flagging marked the 35 mph centerline, yellow
marked the 40 mph centerline, blue marked the 35 mph cut
slope, and orange marked the 40 mph cut slope. The cut slopes
had been staked for a 1/4:1 (horizontal to vertical) which
assumed a rock cut. Both the 35 and 40 mph design results
in the removal of the existing vegetation which would be
nearly impossible to re-establish on a 1/4:1 slope.
Stop No.3 was at China Row, M.P. 385.35 and curve No.7.
China Row is the location of a picnic area and also the tree
canopy over the roadway formed primarily by black willows.
The trees immediately adjacent to the road would be removed
by any roadway widening or alignment improvement. The black
willows are advanced in age and no secondary or replacement
growth is apparent. If the canopy effect is to be maintained,
replacement growth should be started that would conform to
whatever aljgnment is selected. Because of the existing
limited size of the picnic area, the Forest Service would
like to discourage its use. Curve No. 7 immediately upstream
from China Row was marked for both 35 and 40 mph
designs and a 1-1/2:1 cut slope.
Stop No.4 was at Logan Cave, M.P. 386.3 or curve No. 22.
Any flattening of the curve to achieve 35 or 40 mph design
speed would result in encroachment into the river. The existing
channel is already confined with haphazard unattractive
riprap protecting the roadway. Several options for
flattening the curve were discussed including the following:
1. Place the roadway on a bridge-type structure that
would cantilever out over the river. The structure
would extend out to about the center of the channel
and would apply only to the 35 mph design. The
roadway profile would have to be considerably higher
than the existing roadway to provide hydraulic
clearance beneath the cantilevers that would support
the structure girders. Clark Ostergaard showed an
artist's rendering of what the cantilever
structure may look like.
2. - Move the channel of the river by cutting into the
bank opposite the roadway. This would require a
channel change up to 500 feet in length for the
35 mph design speed and up to 600 feet for the
40 mph design speed. A retaining wall along the
roadway would be included for both design speeds.
3. Retain the existing river channel and construct a
bridge over the river for the roadway. This would
require a structure up to 400-feet-Iong for the
35 mph design speed and ssO-feet-Iong for the 40 mph
design speed. The bridge would extend out to the
center of the existing channel for the 35 mph design.
For the 40 mph design the bridge would essentially
cover the channel for about 300 feet. In both
cases the roadway profile would be at least 4 feet
higher than the existing roadway profile to provide
for hydraulic clearance under the structure.
4. Switch the locations of the river and the roadway
by constructing bridges at each end of the roadway
curve. Due to the skew angle at which the roadway
would cross the river, each of the bridges would
be up to 200 feet in length. The bridges could be
shortened by reducing the crossing skew angle by
making some fairly sharp bends in the river at the
5. Horizontal alignment change downstream from Logan
Canyon. This would require a cut into the
It was agreed that additional studies be done in this area
to better define the options. The Forest Service would like
to discourage parking immediately adjacent to the cave and
provide parking near Cottonwood Creek.
Stop No. 5 was at Cottonwood Creek and curve No. 24 at
M.P. 386.45. The narrow structure should be replaced. At
curve No. 24, the relative impacts of both the 35 and 40 mph
designs were discussed. Both would result in considerable
excavation into the hillside with the difference being in
the amount of cut. An additional option identified in the
field was to cut through the ridge that separates the Logan
River and Cottonwood Creek drainages which would probably
involve no more earthwork than the other options. It was
suggested that it should be evaluated.
Stop No.6 was at M.P. 387.1 at curve No. 29. Both the 35
and 40 mph alignments were staked. The hillside at this
location is less vegetated and has no unusual or distinguishing
features. Little difference is evident between the
30 and 40 mph designs. The field inspection showed that it
would be desirable to have the 40 mph design align with the
tangent to the west to eliminate the reverse curve.
Stop No.7 was at M.P. 387.6 just below the lower twin bridge.
It was concluded that the existing alignment be followed to
eliminate the need for additional fill, and if possible to
flatten the existing man-made rock fill slope so that it
could be revegetated.
Stop No.8 was at M.P. 387.9 just above the lower twin bridge
in the dugway. Replacement of the lower twin bridge was
discussed and an option is to replace the bridge with a
structure on a new alignment upstream of the existing bridge.
This would require a new cut through the hill next to the
existing cut, which could be filled and shaped to a naturally
appearing contour with material from the new cut. At
the other abutment it would be desirable to flatten the fill
slopes resulting in encroachment into the flats at the base
of the fill.
In the dugway itself, the development of a climbing land was
discussed which would require either a retaining wall on the
downhill side or cutting further into the hillside. Clark
Ostergaard showed an artist's rendering of how a rock-faced
retaining wall may appear. Cutting into the hillside in the
lower portion of the -dugway may require retaining walls or
other stabilization, because the slope is less stable than
the upper portion of the dugway where the existing rock cuts
appear stable. The most feasible solution may be a combination
of widening the rock cut in the upper portion of the
dug~ay and constructing a retaining wall in the lower portion
·of the dugway.
Stop No.9 was at M~P. 388.4 at the upper twin bridge. The
most feasible location for replacement of the upper twin
bridge would be downstream and as close to the existing
bridge as possible to avoid the riparian areas of the river.
Stop No. 10 was at M.P. 389.9 at Ricks Spring. There was
some discussion about shifting the alignment of the road as
close to the river as possible to permit parking to be
consolidated on the same side of the road as the spring.
Stop No. 11 was at M.P. 393.8 at Tony Grove Creek. The existing
narrow structure would need to be replaced. The roadway
in this section could be widened to provide for a passing
lane with essentially all of the widening being done on the
roadside away from the river.
Stop No. 12 was at the M.P. 396.9 at the lower Beaver Creek
Bridge near the Franklin Basin Road intersection. The existing
narrow structure would need to be replaced on the
existing alignment. The Franklin Road intersection would
also be improved.
Stop No. 13 was at M.P. 397.7 along Beaver Creek. Due to
the relatively narrow area between Beaver Creek and the hillside,
it appeared to be difficult to develop a climbing lane
along Beaver Creek from just above the Franklin Road intersection
to just below the Beaver Mountain Road intersection.
Stop No. 14 was at M.P. 405.1 or Curve No. 85. Both the
35 and 40 mph designs would result in considerable new fill.
The existing fill would need to be removed and used to restore
the cuts on either side of the fill to a more natural
contour. Another alignment was also discussed.
Stop No. 15 was at the Bear Lake Overlook at M.P. 405.8.
The location of Alternative G-3 was pointed out, particularly
the area where the deep cut through the ridge below the lookout
would be located. The problem of flattening the hairpin
curves beyond 35 mph which would result in too steep of a
Stop No. 16 was back down the Canyon at the Burnt Bridge at
M.P. 385.7. The options for replacement of this bridge were
discussed. The consensus was that the bridge should be
replaced at the present location with a temporary bridge
located downstream to carry traffic during construction.
Stop No. 17 was at M.P. 384.8 in the area just above Wood
Camp campground where ·the McGuire Primrose is located. The
Primrose was not yet readily apparent but the known locations
were pointed out extending westerly down the rock outcrop to
within about 40 feet of the existing road. Any proposed
road improvements should avoid this area.
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