South terminus of US 491?

[US 89]

Wikipedia says it's at I-40, and signage on the stoplights at the I-40 junction, as well as the BGSs on I-40 itself, indicate that it ends at I-40. But usends.com suggests that it is at Old US 66 in downtown Gallup, and there is definitely a bit of signage that supports that.

Does anyone know which is correct, or maybe has access to an AASHTO route log that I can't find? I'm curious to know because I'm going to clinch 491 this week and want to know whether or not I can get on I-40 or have to drive all the way to Old 66.

[oscar]

Why not just turn south from I-40 to the exit for Old US 66, and decide for yourself? It's less than a mile south from the Interstate.

[Jim]

It's not much, but here's a link to an unresolved discussion we had on this topic for TM:

https://github.com/TravelMapping/HighwayData/issues/63

[NE2]

http://dot.state.nm.us/content/dam/nmdot/Data_Management/POSTED%20ROUTE-us_routes.pdf