About Us

Mission Statement

Be the leader in the materials supply industry by:

  • Developing and rewarding our team.
  • Operating safely, profitably, and efficiently.
  • Exceeding customer expectations of quality, value and service.

Corporate Values

At Knife River, our success is built on four core values: People, Safety, Quality and our Environmental Commitment.

We are one of the largest construction materials and contracting companies in the United States, a status we could not have achieved without our dedicated customers and our 5,600 team members. People are critical to our success, whether it’s our employees, our customers, or the end users of our products and services.

That’s why commitment to our other values – safety, quality and environmental – is so important. We are driven to work safely, produce quality results and manage our impact on the environment because that is the best way to take care of our teams, our customers and our communities.

Behind every Knife River job stands a team committed to each other, committed to you and committed to our values.

Rock Solid Solutions

When R.S. Sweetman purchased C.A. Wagner Construction Co. in 1952, the company specialized in heavy/highway construction. Later, Sweetman Construction Co. diversified into other phases of road building and heavy construction projects in South Dakota and surrounding states.

Founded in 1930, Concrete Materials produced crushed rock from a small processing plant in west Sioux Falls. The company later added a small sand production plant near Rowena and, after World War II, opened Sioux Falls’ first ready-mix concrete plant adjacent to the original rock quarry. Sweetman Construction Co. purchased Concrete Materials in 1952.

Since its inception, the company has continued growing and expanding. We own and operate aggregate and concrete production facilities in Chancellor, Yankton, and Sioux Falls, where we also have a stone quarry, sand and gravel processing plants, ready-mix concrete plants, and asphalt plants. In 1992, Concrete Materials purchased Brandon Materials Co., operating a ready-mix concrete plant and a sand and gravel processing plant in nearby Brandon, SD. Ellis & Eastern Railroad Co., founded in 1987, also operates in the Sioux Falls market area. In 2005, Concrete Materials expanded into the retail landscaping business. In 2012, Rail to Road was started, placing Sweetman Construction Co. in the business of Transloading. Transloading is the term used for the handling of goods shipped via rail to and from customers not located on a rail line. In 2018, the stock of Sweetman Const. Company was acquired by Knife River Corporation, a subsidiary of MDU Resources headquartered in Bismarck, North Dakota. Sweetman and Concrete Materials were renamed Knife River – South Dakota in 2022.

Knife River – South Dakota is committed to producing only the very best quality materials to serve the construction industry in eastern South Dakota and surrounding states.

  • United Way
  • Big Brothers & Big Sisters
  • Make-a-Wish
  • Muscular Dystrophy Association
  • Habitat for Humanity
  • Sioux Falls Jaycees
  • Sioux Falls Area Humane Society
  • Southeast Behavioral Health
  • Sioux Falls Area Community Foundation
  • Sioux Falls Development Foundation
  • Sioux Falls Area Catholic Foundation
  • March of Dimes
  • Cancer Society
  • Toys for Tots

At Knife River – South Dakota, we believe that building with concrete makes good environmental, as well as business sense. Through the use of best environmental practices, we support sustainability and take responsibility for the world in which we live. Environmentally friendly in many ways, concrete has been used for centuries to build durable structures where versatility and strength are key considerations.

  • Concrete is composed of readily available ingredients including water, aggregate, and cement. Quarries are the primary source of raw materials, and these spaces can be easily reclaimed because extraction of has virtually no byproducts. Often they are restored to their natural state.
  • Concrete is energy efficient, with only modest energy needs. Many concrete products are made from local resources and processed in the area, reducing transportation fuel and handling costs. Once in place, concrete can offer significant energy savings over a lifetime, as its thermal mass, when coupled with insulating materials, helps regulate temperature in buildings and homes.
  • Concrete is a durable building material, becoming stronger with time. This means less maintenance and fewer replacement costs when compared with other materials.
  • Basically inert, concrete has little impact on the environment once in place, making it a renewable and green building material.
  • Concrete itself can be reused and recycled as an aggregate in new concrete mixtures.

While there are many environmental advantages to building with concrete, we are keenly aware of the risks involved and are committed to protecting and preserving the world around us. For that reason, we continually improve all of the products we manufacture to ensure they leave behind only a very small footprint on the environment.

As your partner, we will help you to ensure best environmental practices are followed throughout your building project by:

  • Providing the ideal admixture, using only the appropriate and least invasive chemical additives to achieve the best results.
  • Carefully estimating concrete quantities for your jobsite to ensure efficiency and reduce waste.
  • Avoiding on-site environmental damage to soil and trees.
  • Controlling water runoff to protect topsoil and surface water.
  • Promoting the use of concrete waste as clean fill when possible.

At Knife River – South Dakota, we believe that building with concrete makes good environmental, as well as business sense. Through the use of best environmental practices, we support sustainability and take responsibility for the world in which we live.

  • Association of General Contractors (AGC)
  • South Dakota Ready Mix Concrete Association (SDRMCA)
  • South Dakota Trucking Association (SDTA)
  • National Concrete Masonry Association (NCMA)
  • Quartzite Rock Association
  • Dakota Asphalt Paving Association (DAPA)
  • Sioux Empire Home Builders Association (HBA)
  • South Dakota American Concrete Pavement Association (SD ACPA)
  • Sioux Falls Contractors Association (SFCA)
  • South Dakota Golf Course Superintendent’s Association (GCSA)
  • Sioux Falls Chamber of Commerce
  • Yankton Area Chamber of Commerce
  • Rock Valley Chamber of Commerce
  • South Dakota Nursery & Landscape Association
  • Nebraska Concrete Masonry Association
  • Minnesota (Midwest) Concrete Masonry Association
  • Construction Finance Management Association
  • Asphalt Paving Association of Iowa