Gov. Jay Nixon has vetoed legislation that included designating part of I-70 as "Graham's Picnic Rock Highway."
The governor said a popular outing during the 1880s was to drive horses and buggies to the rock for a picnic. But the rock also has been called "slave rock," which comes from a widespread belief that slave auctions occurred at the site.
Nixon says the highway designation would have elevated one part of the site's history above the others.