Springfield Underground started as a limestone quarry in 1946. Warehousing began in the excavated caverns in 1960, while mining continued. By 1994, the mine had excavated around 2 million square feet, and Springfield Underground was created by its owners to market and further develop it as an underground business park. Today a few dozen companies operate in the space, including Buske, a third party logistics and supply chain company which leases 235,000 square feet underground. A 56,000 square foot data center and co-location facility was built by the local municipal utility, and was sold to Bluebird Networks in 2014. The largest tenant is Kraft Foods. This has been one of their principal bulk cheese storage facilities for decades.