Today, some guys from the office had a discussion about Montana's INTERSTATE speed limit. I remembered that Montana had an 'autoban' type speed limit - - unlimited. But I argued that they changed that law recently.
So - - for those of you who are wondering about the INTERSTATE speed limit in Montana -
"The following speed limits went into effect May 28, 1999 [for Montana]."
http://www.doj.state.mt.us/driving/speedlimits.asp (with chart)