Seattle Wa. to 4 Corners mid to late Oct.

If you want to be a real tourist, you can drive to the actual point where Colorado, Utah, Arizona and New Mexico meet. There's a plaque in the ground on that point. You can take pictures of yourselves standing with your heels in two states and your toes in the other two at the same time. There's nothing else there. Big Whoop. It wasn't worth the drive. I've read reports that the plaque isn't even in the right place.
Here's a link.

Mootpoint wrote:
Seattle Wa. to 4 Corners mid to late Oct.

We are considering going in this direction on our way south this year probably through Salt Lake City.
Does anyone have any suggestions as to routes/highways and possible weather warnings.:h
We have a Ram 3500 4x4 diesel and a 35' 5th wheel.

Of the 4 possible "corner" areas, I think that Cortez/Mesa Verde/Durango/Telluride area would be the best of the 4, followed closely by the Moab/Bluff/Monticello area and access to the National Parks in the area. AZ and NM are more desert areas, and while beautiful in their own way, for many folks they are an "acquired" taste. There are more mountains in UT and CO to break up some of the sameness of the desert.

Weather in those areas can be very changeable. This time of year and going in to October, we here in Colorado keep an eye on low pressure systems that come across AZ and NM and set up in the OK panhandle, for nasty weather to hit along the eastern Front Range. That nastiness usually hits the 4 Corners area a day or two prior, so watching forecasts for the Flagstaff area would certainly be appropriate. Systems come primarily from the W/SW that impact the 4 Corners.

There's several routes you could take from SLC, just depends on how much time you want to spend driving, and on what kind of roads.

Mootpoint, I can't help you on travel routes. The weather, no one knows for sure.
We are heading that way about Sept 20 from Branson Mo. I like to think that when someone asks about "Four Corners" they are wondering about the entire area.
IMO, red rock country is Gods country at it's finest.
It's been more than 10 years, can't wait to get back and see some "RED ROCKS".
Enjoy your travels, We enjoy ours.

Is there some compelling reason to visit the Four Corners at any time of the year? It's a vast wasteland. The only reason to visit there is the taco pizza.

I'm not sure where 4 corners is, but you should be fine at that time.