The One Minute Geographer: The Great Plains — The Mixed Grass Prairie

Jim Fonseca
2 min readOct 13, 2021
The mixed grass prairie, center, under the 100th meridian. Map from Wikipedia; line drawn by the author.

We’re continuing a series of posts about the 100-degree meridian, shown above running through the ‘mixed grass prairie’ of the Great Plains. The mixed grass prairie is an ecotone, a zone of transition that lies between the tallgrass prairie to the east, shown in dark green, and the shortgrass prairie, shown in light green to the west.

These are three zones of natural vegetation, now greatly modified by agriculture. It makes sense that the tallgrass prairie lies to the east, an area of greater rainfall. That zone has become the corn and soybean belt. The mixed grass prairie tends to be better for wheat and, as rainfall decreases to the west, it’s mostly used for grazing.

Tallgrass prairie in eastern Nebraska. Photo from the Prairie Corridor Foundation on

But a lot of the Great Plains takes advantage of irrigation — often irrigated crop circles. Irrigated areas have a much greater variety of crops. In all these agricultural zones the biggest income producer for farmers is often livestock, particularly beef cattle on the Great Plains and hogs in the former tall grass area.

The term ‘mixed’ doesn’t necessarily mean that the height of the grasses is mixed in all areas. One or the other usually predominates, so in the mixed region, depending on local climate, soil, and elevation, the natural vegetation may have been acres of tall grasses here and acres of short grasses there.

Shortgrass prairie in western Nebraska. Photo from

The mixed grass prairie zone has greater biological diversity, not only of plants, but of birds and other animals as well. That’s why botanists call it an ‘ecotone’ — a zone of transition. I’ve included photos of both the tallgrass and the shortgrass prairies.

We’ll look at how the 100th meridian corresponds with elevation in this next post in the Great Plains/Magical Meridian series

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Jim Fonseca

Geography professor (retired) writes The One Minute Geographer featuring This Fragile Earth. Top writer in Transportation and, in past months, Travel.