07/06/2026
River Valley Ranch Mushroom Farm, from a slide that was made in June of 1991 by the KADC.
River Valley Ranch originally opened in 1971 as a horse farm but closed in the winter of 1974 after eight horses were found starving and one starved to death, left outside in the snow for who knows how long. The owner responsible was found guilty of cruelty to animals.
In the summer of 1975 it was sold to Bill Rose and Mitchel Slonina. And the mushroom farm, on Hwy 50 immediately west of the Fox River, opened in March of 1976.
Slonina was an experienced mushroom farmer, having spent 29 years growing them in Illinois. And Bill Rose operated a restaurant in Elk Grove and couldn't get good mushrooms. They began growing mushrooms in what was then a new way, a way folks with a home mushroom kit are familiar with: with plastic bags of fertilizer.
Mushrooms are the spore-bearing fruiting body of a fungus. But despite having "fruit" in the description, they are more closely related to animals than plants. About two billion years ago, eukaryotes (we're eukaryotes) diverged from prokaryotes (e coli is a prokaryote) when an archaeon (a domain of single-celled life which are common in geothermal sites) formed a symbiotic relationship with a bacteria (that bacteria became mitochondria). Around a billion years later, some evolved flagella on their reproductive cells and became opisthokonts, this separated animals and fungi from plants. And animals and funguses diverged from there. Both animals and fungi store energy in glycogen while plants use starches. Both animals and fungi respire through consuming oxygen and external organic matter, whereas plants make their own food with photosynthesis. And fungi use chitin like arthropods do.
I've read that many people think it's wrong to say that a mushroom is "meaty." But it is high in umami: the fifth taste our tongues can pick up, which is best described as a comforting savory taste. There's no English word, like there's no English word for hygge, and no English word for schadenfreude. And none for "tsundoku" which is the act of collecting reading materials in your home but piling them up instead of reading them. It has a positive and aspirational tone: you're eager to learn but you just don't have the time, and instead you're building a collection from which you can pull the perfect book when the time comes.
By 1977, the farm produced 700 pounds of mushrooms a day. And 90% of those went to a mere six restaurants. The remaining 10% were sold in their on-site store.
When the Highway 50 relocation was unfolding in the mid-80s, they were displaced. And moved to Hwy P and Hwy 50 in Slade's Corners. By 1989, they had moved to the new location and had seven grow houses with 30,000 square feet of growing space, producing 10,000 pounds a week.
They're still there. They apparently also grow h**p now. Betcha city kids sneak around and only find a headache.
