There are mineral springs, especially salt springs, in various parts of the state, particularly in the Blue Grass Region; these are now of comparatively little economic importance; no salt was reported among the state's manufactures for 1905, and in 1907 only 736,920 gallons of mineral waters were bottled for sale.
The high price received by the hill growers of the Burley induced farmers in the Blue Grass to plant Burley tobacco there, where the crop proved a great success, more than twice as much (sometimes 2000 lb) being grown to the acre in the Blue Grass as in the hills and twice as large patches being easily managed.
On the escarpment around the Blue Grass Region the soils are for the most part either cherty or stiff with clay and of inferior quality.
In the Blue Grass Region many thoroughbred shorthorn cattle and fine mules are raised.
This Blue Grass Region is like a beautiful park, without ragged cliffs, precipitous slopes, or flat marshy bottoms, but marked by rounded hills and dales.
The best soils are the alluvium in the bottom-lands along some of the larger rivers and that of the Blue Grass Region, which is derived from a limestone rich in organic matter (containing phosphorus) and rapidly decomposing.
The additional production of the Blue Grass Region sent the price of Burley tobacco down to this figure and below it.
Or more to the famous Blue Grass Region, in which erosion has developed on limestone a gracefully undulating surface.
Around Lexington is especially rich; outside of this area the Blue Grass soil is less rich in phosphorus and contains a larger mixture of sand.
The remainder of the state which lies east of the Tennessee river is divided into the Highland Rim Plateau and a lowland basin, eroded in the Highland Rim Plateau and known as the Blue Grass Region; this region is separated from the Highland Rim Plateau by a semicircular escarpment extending from Portsmouth, Ohio, at the mouth of the Scioto river, to the mouth of the Salt river below Louisville; it is bounded north by the Ohio river.