Highway 385 snakes, rises and falls as it traverses the pine covered slopes of the western Black Hills of South Dakota. A main arterial that directly connects all of the major tourist attractions in the Black Hills region, a 6-mi. (9.6 km) portion of the 120 mi. (193 km) of the road, just south of the popular tourist town of Deadwood, is now undergoing a complete reconstruction. The road carries a high volume of traffic during the summer travel season. Mixed in with the tourism traffic is a considerable amount of logging traffic.
Once complete, the new construction should alleviate congestion and improve traffic flow through this portion of the highway.
E. H. Oftedal & Sons Inc. is the general contractor for the project. Oftedal, with offices in Montana and Wyoming, is primarily a grading and crushing contractor. Its main clients are the transportation agencies in Montana, Wyoming and South Dakota. Oftedal also undertakes construction projects for the mining, railroad industries and miscellaneous private enterprises.
According to Steve Schelske, project engineer of the South Dakota Department of Transportation (SD DOT), the scope of the project includes re-grading through the existing corridor and shifting offline in some areas to provide shoulders, guardrails, improve sight distance and drainage. And to move traffic a little faster, it will include climbing lanes on a portion of the road called Strawberry Hill. Along with the road improvements, five box culverts will be replaced and a bridge deck overlay will be completed on a 55-ft. (17 m) bridge at the north end of the town of Deadwood.
Approximately, 72,000 tons (65,317 t) of sub material will be used for the road base with 71,000 tons (64,410 t) of base course. The driving surface requires a lift of 11,600 tons (10,523 t) of Class S concrete and two lifts of approximately 32,000 tons (29,030 t) of Class Q-MVT concrete.
“The existing roadway was narrow, only 22 feet wide, no shoulders with a winding road and steep grades,” Schelske explained. “The new climbing lanes on both sides of Strawberry Hill will improve traffic flow.”
The climbing lanes on Strawberry rise more than 1,000 ft. (305 m) at a grade between 5.7 to 6.9 percent.
Total estimated construction cost is expected to be $18.2 million. The funding is split out to collect $1.7 million from the Bureau of Reclamation, (for the extra waste haul and related road work haul), $3,312 from the city of Lead, $13.5 million from TEA-21 federal funds, and $2.97 million from SD DOT matching funds. The state has spent an additional $800,000 to date for project engineering. Another $1.5 million of state funds is set aside for right of way and utility work.
Construction began last May. Work will continue through July 30, 2003. Schelske expects the road reconstruction to be completed on time.
Unlike much of the state, which is flat, relatively tree less and stretches east for several hundred miles, the Black Hills rise 4,000 ft (1,219 m) vertically from the surrounding prairie and are covered with pine timber. And where the road network is mostly laid out in simple horizontal and perpendicular lines throughout most of the state, the vertical geography of the Black Hills pretty much dictates highway design. Road construction in hilly terrain requires the removal of a far greater percentage of earth than in the flatter geographical areas of the state.
The geology in the hills is primarily metamorphic rock with so much structure that in a matter of just few feet the bedding changes from horizontal to vertical, Schelske said.
Schelske estimated that approximately 1.3 million cu. yds. (993,921 cu m) of mostly rock material will be moved. Of that amount, approximately 500,000 cu. yds. (382,277 cu m) is excess. As of November 2002, 90 percent of the waste haul had been completed.
“The excess dirt and rock will be hauled to the Gilt Edge Mine and used by the Environmental Pollution Agency (EPA) to place a cap on top of their Ruby Gulch superfund site,” Schelske explained. The Gilt Edge Mine formerly mined gold.
A road project of this nature in hilly terrain requires mammoth and rugged equipment for the excavation phase of the project.
Hal Fuglevand, site project manager of Oftedal, said that the sometimes tight working conditions and steep grades challenged the heavy equipment used on the job.
“We have used eight of our Cat 769C 35-ton rigid frame end dump trucks for most of our rock hauling. These trucks have worked well in tight areas and steep grades,” Fuglevand said. “We also utilized three rented Volvo A30 arctic trucks and two Cat D300s for a lot of the terrain that was too steep or too narrow for the Cat trucks.”
Oftedal brought in a Hitachi EX 400 and EX 750 and a newly purchased Zaxis 800 along with Cat 988B and 980G front end loaders for excavating.
“These have been very good excavators because much of the material has been shot rock or ripped rock,” Fuglevand said. He added that several Cat motorgraders supported the hauling and excavation work.
Oftedal subcontracted with American Mine Services of Boulder, CO, to blast and loosen the solid rock lying beneath the ground cover of the hilly terrain.
Oftedal mustered six of its 14 Cat D9L crawler tractors from its fleet for its dozing and ripping operations.
“We like the size and power of these tractors,” Fuglevand explained. “Although they are not new, we are able to keep them in good running order by cycling them through our shop in Casper, WY, for maintenance.”
The dry, rainless summer allowed for good construction conditions. These conditions turned against the contractor, however, last July when a 11,000-acre (4,451 ha) forest fire broke out in the area of Grizzly Gulch near Deadwood and one ridge over from the road construction. The fire forced construction crews to shut down for approximately a week.
Despite the week-long delay in construction, Schelske is confident that the completion date can still be met.
“The delay due to the Grizzly Gulch fire caused the DOT to scale back the scope of the work that will be accomplished this year but we are still optimistic that if we have typical weather for the remainder of the project that we can complete it on time,” Schelske said.
Fuglevand reiterated Schelske’s satisfaction with the progression of the construction.
“Work is progressing well,” Fuglevand said. “Despite some problems this past May into July with heavy traffic volumes and some utilities that had not been moved out of the work areas.”
Fuglevand credits the construction crews and SD DOT staff for keeping the road construction on schedule.
“We have a very dedicated and hard working crew who have been the main reason for our success on this project,” Fuglevand said. “Ken Mumbower, Oftedal project superintendent, has been the driving force on this job. The SD DOT has had a professional and equally hard working staff. Together, we have managed to work through many difficult situations on this project.”
Widening a highway on a hillside that is adjacent to several creeks presented some challenges to the design and construction crews.
Among these was a site the DOT Foundations office identified where the rock was unstable so cutting through this portion of the hillside was not an option, Schelske said. This forced the designers to widen toward the creek and relocate a portion of it.
“Stream relocation involved moving the alignment of the channel with very specific considerations including fauna, flora and erosion control. The new channel is specifically designed to match the natural environment of the stream,” he explained.
Construction crews are currently building a Mechanically Stabilized Earth (MSE) wire face wall nearly 2,000 ft. (610 m) long and up to 30 ft. (9 m) high throughout a portion of the stream relocation.
The combination of rural and urban settings along the project which includes 110 parcels of land with 67 different landowners, also brings to the project many non-technical issues that are handled throughout the life of the project, Schelske said.
Construction crews have had to balance the needs of the landowners, which include changes to their properties, landscaping and access, while maintaining the progress of construction during the peak tourist season.
Cutting and grading into the hillside along portions of the road construction also forced construction crews to bring down stands of timber. The sweet scent of freshly cut pine wood overpowered the pungent odor of diesel fumes while crews cut and loaded the pine timber into waiting trucks.
Schelske estimated that crews cut 282,000 CCF or 525,000 MBF of merchantable timber while 10,000 CCF or 45,000 MBF of wood products other than logs were cut.
After construction was suspended for another week in August during the Sturgis motorcycle rally, which brought in more than a half million motorcyclists to the hills, construction crews closed a 2-mi. (3.2 km) section of the road to traffic for three months.
During the road closure, work went fairly well, Fuglevand said, despite mother nature dumping 16 in. of snow in the region back in October and November. Crews re-opened the road this past November.
The final phase of grading operations will resume this spring along with the paving work. Fuglevand and Schelske expect the construction to be completed by Aug. 1.