"Boonslick is a significant natural spring, salt lick, named after Daniel Boone's two sons, Nathan and Daniel Morgan Boone. This spring was one of the primary sources of salt for the Indians in the central Missouri area and for the early settlements along the Missouri River between 1806 and 1833. The site is also significant as it was a stopping point for travelers along an ancient Indian trace which became an early highway from St. Charles west ward across Missouri, known as the Boonslick Road. The area around the salt lick, presently Howard County, became known as the "Boonslick Country," and was a prime settlement area in the early 1800's.
The springs were included in a Spanish land grant of 400 arpents to James Mackay on May 21, 1797. Mackay, a native of Scotland, was commissioned by the Spanish Governor to explore the upper Missouri River between 1795 and 1796, and may have discovered the salt springs at this time. However, it is probable that French trappers, traders and explorers who came into central Missouri earlier in the 18th Century learned of the springs from the Indians.
Nathan and Daniel M. Boone began boiling the water for salt at the site in 1806. At this time they had one furnace with forty kettles Which required six to eight men to operate. The brothers produced from 25 to 30 bushels of salt per day. This was shipped to settlements along the Missouri River and to St. Louis where it sold for $2.00 to $2.50 per bushel. The salt works were later expanded by enlarging the existing furnace and erecting a new one, enabling each furnace to hold sixty kettles. The operation of these furnaces required from sixteen to twenty men; each furnace produced about 100 bushels of salt per day. According to Boone, 300 gallons of water were required to make one bushel of salt.
The method used by the Boone brothers in manufacturing this salt is not definitely known; however, descriptions of contemporary salt works indicate that the water was first boiled until almost all was evaporated. The remainder was then placed in the sun or "salt house" for natural dehydration.
This procedure of salt production and manufacturing at such a distance from the population centers did not prove profitable for the brothers. In 1810 Daniel M. sold his interest to James Morrison of St. Charles. Nathan continued in the venture with Morrison, but in the fall of 1811, he also disposed of his interests. Nathan attributed the failure of the salt works to the troubles and pilferings of the local Indians "... chiefly in stealing and killing the working and beef cattle." These work animals were replaced by going downstream 150 miles to the nearest settlement, while the works remained idle.
Between 1812-1834 Jesse and James Morris on worked the salt lick, operating on the same scale as the Boone Brothers.
After the Morrisons' enterprise, the lick remained idle until 1869 when the Boonslick Salt Manufacturing Company was organized. This company conducted rather extensive drilling operations at the site, digging one of the springs to a depth of 1001 feet. However, when the water from the well was chemically tested, it was found to be insufficiently saline to support the operations. The salt works being situated quite a distance from a large population center also prompted the company to dissolve in 1879.
The only other attempt to utilize the salt lick was at the turn of the century when an attempt to stock the lick with oysters and salt water fish proved unsuccessful.
In 1959, an eight acre tract which included the salt lick, was donated to the State of Missouri for use as a state park." [This area has now expanded to 51 acres] - National Register Nomination form