On a Saturday morning in early October, the campus of South Dakota Mines will open its doors to anyone who wants to walk in. There is no ticket, no registration barrier, no age limit. Families can pan for gold, dig in a sandbox mine, watch a blacksmith work, and wander through the university's Museum of Geology for free. It is, on its face, a pleasant autumn outing in Rapid City.
It is also something more deliberate than that. The event is called the 4M Expo Discovery Day and Open House, and the four M's stand for mining, minerals, munitions and manufacturing — four industries that share supply chains, workforces and engineering problems but rarely share a room. The expo is designed to put them under one roof and, more pointedly, to put them in front of the public.
The story of how it got there starts with a school that was built to feed a gold rush. South Dakota Mines was founded in 1885. What began as a mining school has spent well over a century growing into something broader, and the 4M Expo is the university's attempt to say so out loud.
That message has taken on a sharper edge in the past few years. Mining has moved from the periphery of public attention to the center of a national conversation about critical minerals — the elements buried in the Earth's crust that end up in cell phones, electric vehicles, surgical equipment and weapons systems. As university officials have framed it, the mining supply chain has been brought to the forefront of national security, and the demand for these materials is climbing.
The first 4M Expo was held in October 2025 in the Nucor Mineral Industries Building, a facility that itself tells part of the story. Nucor Corporation gave South Dakota Mines $5 million toward the building — the largest corporate gift in the university's history — and the school cut the ribbon on the finished structure in April 2025. The building was designed with state-of-the-art teaching and research space, and it is where the expo's demonstrations, keynote talks and hands-on stations are staged.
For Andrea Brickey, a professor of mining engineering and management at Mines, the point of throwing the doors open was straightforward. "We really want the community to come to campus and see some of the really cool things our students are doing for national security, agriculture and the environment," she said ahead of the inaugural event.
That inaugural expo drew students, faculty and industry leaders together, and it drew a line connecting the four M's that organizers say is often invisible from the outside. Shelly Rose, who handles human resources and community relations for the Coeur Wharf Mine, put the multiplier this way at the 2025 event: "For every one mining job, it creates three to four other jobs. So, it's really important to have that innovation in all areas."
The expo also arrived at a moment of change inside the university itself. South Dakota Mines President Brian Tande described a curriculum shift aimed at replacing tests, homework and quizzes with real projects where students create new value in some form. Those updates were set to begin the following fall, running alongside the development of the Rapid City Downtown Innovation District. The 4M Expo, in other words, was not just a showcase of what Mines already does — it was a preview of where the school intends to go.
There is a practical reason the university can make this case with unusual authority. South Dakota Mines is one of only five universities in the nation to house all three mineral industry disciplines under one institution: geology and geological engineering, mining engineering and management, and materials and metallurgical engineering. Few places are positioned to talk about the full arc from ore body to finished material, and the expo is built to show that arc to people who may never have thought about it.
The federal government has been making the same argument with money. South Dakota Mines is set to receive $25 million to expand mining education and workforce development, part of a broader federal investment of more than $180 million aimed at strengthening the nation's critical minerals workforce and increasing domestic production. The $25 million comes from an $80 million Department of War funding pool shared among three universities and will establish the Critical Minerals Merit Scholars Consortium, a workforce initiative involving South Dakota Mines, the University of Kentucky and Missouri University of Science and Technology. Rudra Mitra, interim head of the university's Department of Mining Engineering and Management, represented Mines at the announcement. "South Dakota Mines is proud to be selected for $25 million in funding to establish the Critical Minerals Merit Scholars Consortium," Mitra said.
Set against that backdrop, the free open house reads less like a recruiting fair and more like a translation exercise — taking a subject usually discussed in terms of national security and supply chains and reducing it to something a child can hold in a pan of water. The 2026 edition, scheduled for Saturday, Oct. 3, from 10 a.m. to 3 p.m. on the Rapid City campus, keeps the same formula: demonstrations and hands-on activities across mining, minerals, materials, metallurgy and engineering, with free admission to the Museum of Geology in the O'Harra Building.
For families, the appeal is obvious and uncomplicated — gold panning, sandbox mining, blacksmithing, and the chance to talk with the students and faculty who do this work. For the university, the wager is that a few hours of hands-on curiosity will do more than any brochure. The minerals in a phone, a car or an operating room had to come out of the ground somewhere, by someone. The 4M Expo is an invitation to meet them.