Photo courtesy of David Backlin (taken March 2007)
David Backlin calls this a "60's style" trailblazer. It's for US 190 at Lobdell, Louisiana, near Port Allen. This route is on a loop that circles under 190 and also connects to Louisiana 415. You can also see the remnants of a "To East 190" trailblazer behind it. This sign may, in fact, be turned in the opposite direction of where it should be.