Many people who came to St Louis were just passing through and continuing on west. Fur trappers in 1764 extended an Indian trail from the City of St Louis all the way to the Missouri River and called it St Charles Rock Road. St Charles Rock Road was used by many to connect to the Sante Fe Trail, the Oregon Trail and the California Trail. Today the portion of St Charles Rock Road that is east of Lucas and Hunt Road is now named Dr. Martin Luther King Drive.
Across the Missouri River, some of the Boone family continued the trail west to Franklin in Howard County Missouri. Daniel Morgan Boone and Nathan Boone, Daniel Boone's sons, followed what was an Indian path and discovered a salt spring near Franklin Missouri. They called the salt spring Boone's Lick, thus giving the road the name of Boone's Lick Road. The Boone's set up a business and sold the salt that was harvested from the salt spring to those heading further west. Before refrigeration, salt was the only means of preserving food and curing meat so it was a very important commodity. In 1827, Boone's Lick Road became an official state highway and was an important corridor of travel for over 40 years.
In Franklin Missouri the trail then connected with the Sante Fe Trail that traders, with wagon trains filled with goods, used as a trade route to travel to Sante Fe New Mexico (which was in Mexican Territory at the time). Others continued on to Independence Missouri to connect with pioneers heading west on the Oregon Trail. Those who were caught up in the Gold Rush fever would head south on the California Trail once the Oregon Trail crossed the Rocky Mountains.
In 1913 the Daughters of the American Revolution placed markers along the Boone's Lick Road where stage coach stops, forts, outposts, taverns and other sites had been located that were important for westward travelers.