The glacial boundary enters Kentucky in Campbell County, crossing the Ohio River about two miles north of the Pendleton county line. I have not examined sufficiently the northern part of Campbell county, and I can only fix the limit near the river. We crossed the river from New Richmond, in Ohio, and ascended through the channel of a small brook to the summit of the Kentucky hills, near Carthage. These hills are about four hundred feet above the river, and the ascent is very steep. Granitic pebbles were numerous in the bed of this small stream, and, upon reaching the summit, we found the surface covered with till to the depth of ten or fifteen feet, in which granitic boulders a foot through were numerous, and in which it was not difficult to find beautiful specimens of scratched stones. From this point we went south, keeping upon the summit of the plateau from one and a half to three miles from the river. Indications of glacial action continued, but in a somewhat diminishing degree, until reaching Flag's Spring, where they ceased entirely. But to make sure, we went on in the same direction about four miles farther, and came down to the river at Motier, without seeing any farther glacial marks. At Flag’s Spring there is an extensive accumulation of post-glacial conglomerate like that at Split Rock, soon to be described.
from George Frederick Wright's The Glacial Boundary in Ohio, Indiana, and Kentucky, 1884. You can read it all at Google Books