New in September 2002, the interchange of Missouri 22 with US 63 features markers such as these. The 22 is in a narrower font than usual, isn't centered in the state outline, and uses a "pointy" style marker rather than the usual state outline. The now-standard narrow white border is also missing from these markers.
The "pointy" marker style is notable for having less detail on the outline for the west side of the state but more detail on the outline for the east side of the state.