The driving distance between Las Vegas, NV and Denver, CO is approximately 765 miles. The driving time would be approximately 13 hours if you were to travel non-stop in good driving conditions. (The driving time does not take into consideration conditions which may extend trip time such as weather, road work, border crossings and rush hour traffic in urban areas.)
According to MapQuest there are 750 miles from Las Vegas to Denver following I15 and I70
749 miles
about 750 miles
It is 749.24 miles accordng to MapQuest.
It is 750 miles.
752 miles
About 325 road miles.
It is 327.90 miles according to MapQuest.
760 miles taking this route:Go up to I-70 WEST towards DENVER, from Aurora.Take I-70 WEST to I-15 SOUTH to LAS VEGAS at the END of I-70 in UTAH.Take I-15 SOUTH to LAS VEGAS.
Source: Time and Date.com
It is 753 miles according to Google Maps.
Most local people will agree that about 750 miles is the appropriate answer.