I'm interested in what route to take between Denver, Colorado and Salt Lake City, Utah, and vice-versa.


It would seem like there is one northern option and two southern options.

  • In the north, I-25 in Colorado to Wyoming, and then I-80 throughout Wyoming and into Utah.

  • In the south, I-70 in Colorado, then

    • either SH 13 and SH 64 in Colorado, and US-40 in Utah,
    • or, more I-70 / US-50, through Grand Junction, CO, and US-6 in Utah.

What's the difference between these ways, and which one is better, or best avoided? I'm driving in the summer (June 2013); interested in a short route; a little scenery wouldn't hurt; too much engine and tyre wear, bad roads and bad fuel economy is best avoided (driving own car), but high highway speeds are welcome; planning to drive in one or two days, possibly stopping along the highway to get some sleep (spots with night temperatures of around 20°C are welcome, and so are spots where you can get some shade during the daytime). Also, last, but not least, it wouldn't hurt if the route has some T-Mobile USA UMTS, EDGE or GPRS coverage (without classified as roaming).

As far as Google Maps go, it seems like all three routes are roughly the same, in both the time and the distance, so, looking for some more feedback. For DEN⇆SLC, I've so far taken I-80 once when eastbound and I-70 w/ US-6 once when westbound (I've only had one SLC⇆DEN trip).

  • 3
    Let's start from the obvious. Time en route is different, mileage, speed. Is that what you were looking for? If not please provide criteria for better and timeframe you will be taking it.
    – Karlson
    Jun 18, 2013 at 2:09
  • T-Mobile USA has coverage for most of the I-70 route through Grand Junction, CO, but not for the other two routes -- a point to consider.
    – cnst
    Jun 18, 2013 at 19:49
  • 2
    why don't you improve your question? Remove all "best" and "better". Add the first obvious differences you target, length, duration, ... Add you wonder about lookouts or scenic routes, pavement quality, ... Or whatever someone else can think about. In any case, remember YOU are supposed to make the choice, not the others, so ask for the differences, not for the better route!
    – Vince
    Jun 18, 2013 at 20:23
  • @cnst There are great many travelers that take road from Denver to Salt Lake City that have a lot of experiences, truckers look for the longest but fastest route, nature lovers for the most scenic, people that just want to get to SLC looking for the fastest for the time, people that want extreme driving conditions will only be driving it in the winter... Collectively we have absolutely no idea what you're looking for, we're no psychics, so there is no reason to be annoyed just clarify what you're looking for.
    – Karlson
    Jun 18, 2013 at 22:43
  • Beware that the southern routes climb to 10,000'. This could be an issue for people who are sensitive to altitude. Jun 19, 2013 at 20:44

3 Answers 3


Nobody is talking about traffic. The traffic on I 25 between Cheyenne and devore is absolutely horrendous. Either direction. Especially during rush hour. I am a truck driver and I avoid it at all costs, if at all possible. Going I 70 will give you some of the best scenery this country has to offer. Take a break at the rest area at the top of Vail pass. You won't be disappointed. All that being said. I 70 between Denver and the Eisenhower tunnel can be just as horrendous as I 25, as far as traffic goes. If I didn't have to drive a big truck I would try us 40. Again some of the greatest scenery in the country. And I would think far less traffic than either of the other 2 choices.


Based on your criteria, the I-70 to US-6 route appears to be superior.

  • This route has T-Mobile 3G coverage along most of its route, whereas I-80 has little or no data coverage west of Cheyenne.
  • This route is slightly shorter, though the difference in distance is trivial. As both routes travel through mountain passes, fuel usage should be similar between them.
  • Aside from far eastern Utah and far western Colorado, this route has many possibilities for scenic overlooks, stopping points, etc. The Wyoming route has a similar stretch of nothing, so it's even either way; neither route has a good "halfway" point that's approximately half way. Thus I'd recommend starting in the morning and making a one-day drive of it, by either route.
  • If you start your westbound trip in the morning, the afternoon sun won't be in your eyes as you travel north on US 6 into Salt Lake. Nor, when you leave Salt Lake in the morning, will the morning sun be in your eyes as you travel south on US 6.
  • US 6 is divided highway (dual carriageway) much of the way (about 2/3 of the distance) from I-70 to Salt Lake City. The state highways won't be.

Here's some things to consider.

  1. Some people go I-80 to Laramie and down through Fort Collins into Denver. However, Fort Collins has developed and more stoplights will slow you down. Now some people elect to go to Cheyenne and then down I-25 but this adds some distance.

  2. Where you want to go/or traveling from in the Denver area is a big factor in your decision. If you want to say go to Lakewood or Littleton, it might be faster to go I-70 from anywhere in Salt Lake. But if you are going to say Thornton or Broomfield or Aurora, it might be slightly faster to go I-80/I-25.

  3. Most people prefer the scenery of I-70. It is a bit tougher on the car but the scenery is more varied and the elevation changes more extreme. Both routes can be brutal in winter with different challenges. However, I-70 from Denver to Vail can be especially difficult on Sunday evenings or Friday afternoons depending if you are going toward/away Denver, where the I-25/I-80 routes are more consistent with traffic.

  4. On I-70 there will be more tourist opportunities from the Grand Mesa to Vail to Silverthorn, and on the Utah side you can even slip down into Moab and visit Arches.

  5. Take into account construction. Both I-80 and I-70 have seen plenty of it but the I-70 construction seems to be a bit more complicated with more delays. I've sat in my car for nearly an hour getting through Glenwood Canyon, another great scenic destination by the way.

  6. From Green River to say the Wasatch front, you will spend time on U.S. Highway 6 a divided Highway which is a dangerous highway statistically. Usually you can travel by decent rate of speed but it is a two-way highway nonetheless. Same goes from Laramie down to Fort Collins cut off but the distance isn't as great and as I said some people stay completely on the freeway by going all the way to Cheyenne and than taking I-25.

  • If you want to see some different but spectacular scenery you can take Highway 40 but it will add at least two hours to your trip on a divided highway. But the Yampa Valley is spectacular and some of the towns like Steamboat and Kremmling people find charming stops. May 29, 2016 at 17:06
  • funny you mention the construction -- i, too, sat in i70 for like an hour during some construction just off of denver near the mountains. it was so annoying! (i wonder if it was the same construction we both been through!)
    – cnst
    May 29, 2016 at 19:32

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