The rapid growth in Wisconsin’s frac sand industry is slowing, thanks to lower prices and increased supply. The sand is still in demand, but people who expected that they could get rich quick on the state’s sandy soils may be disappointed.

Currently, there are no official employment numbers for the state’s rapidly expanding frac sand industry. But the Wisconsin Center for Investigative Journalism, using job-site estimates developed by the Wisconsin Economic Development Corporation, found that when existing mines and those being built are fully operating, the industry will employ about 2,780 people — a sizeable number given the state’s overall luckluster job picture.

Frac sand fever has hit much of west-central Wisconsin, catching residents and local governments by surprise when demand for sand suddenly soared and permit applications began to pour in. The number of Wisconsin frac sand mining operations has more than doubled in the past year.

What one frac-sand mining company is doing to help protect Wisconsin’s endangered Karner blue butterfly.

Overview of permits required to operate a frac-sand mine.

Resources to learn more.

There’s a new wrinkle in Wisconsin’s fast-growing frac sand mining: It turns out that an endangered butterfly, the Karner blue, lives in the same region. And some companies may be failing to check for the butterfly as they move ahead with mining operations.

This western Wisconsin community is in the midst of a land rush — call it a sand rush — fueled by exploding nationwide demand for fine silica sand used in hydraulic fracturing of oil and natural gas. At least 16 frac sand mines and processing facilities are operating, and an additional 25 sites are proposed, in a diagonal swath stretching across 15 Wisconsin counties from Burnett to Columbia, the Center has found.