Cell phone coverage in Alaska?

Hmm, I hadn't thought of coverage in the Yukon. I think Sasktel uses GSM, not CDMA. Not anymore, anyway. I had a long talk with a Sasktel tech about the Verizon thing. Sasktel is pretty responsive to customer feedback. When AT&T abandoned a HUGE swatch of northern Montana and left them with Sagebrush (and thus Sasktel customers with no coverage down there), it wasn't long before Sasktel developed a roaming agreement with Sagebrush. So I figured I would have a chat with them about Verizon, but the hardware is different, so it's not likely going to happen.
Sasktel roams with AT&T and T-Mobile, but not at all with Verizon or Sprint. My iPhone 6 is unlocked, but it's been so squirrelly with tech issues that we would be reluctant to change SIM cards. We have an iPhone 5 that was my husband's, and we no longer use it, but it is unlocked. We would be bringing the 5's with us anyway as backup (that's how much I distrust my 6...I've had to use my 5 already while waiting for Apple to replace a defective 6). If we have to, we could put a prepaid SIM in there and use it.

A lot of it will depend on which technology your SaskTel phone uses--CDMA or GSM, and then which frequencies it uses.

Typically AT&T and T-Mobile are GSM, and Verizon is CDMA. In Alaska we have both technologies. GCI is the main carrier up here (mostly GSM, but they are also operating Alaska Communications' CDMA network. ATT & Verizon also have presences up here. Not sure if you can get your SaskTel number to roam up here, but if your phone is unlocked, you might be able to activate pre-paid service for your stay.

FYI, as far as I know, Yukon only has CDMA (no GSM) network coverage.

Thank you for your responses, everyone. :)

We have uscelluar at home, which we were told has no coverage in Canada. After some research and a stop at an AT&T store, they assured us we'd be covered using their service. So we bought a cheap phone and one months service. We had very limited service in BC and none in Yukon.
The lesson we learned:just pay the $3 extra per day to uscelluar while in Canada. In Ak, we've had just about as good of service as anyone else using various other carriers.

In 2014, I had good Verizon coverage all over Alaska even having 4g in Denali. We did not have our phones turned on in Canada.

We have AT&T and Verizon up here. My wife and I have both and coverage varies between phones and locations when remote. In towns both work great. No Sprint coverage up here for those that use them.

AT&T used to be much better than VZ in AK, don't know if it's still that way, or not. Most highways & tourist areas are covered. It will help if you use a booster like a Wilson Sleek.

I'm with the last two posters on this as I have used both Verizon and ATT&T and got similar coverage.

I got Verizon coverage only in the major cities/towns. Very sparse.

Our last trip was in 2013, and we had AT&T. Had coverage where coverage was available, which was very limited. Had it in Anchorage and Fairbanks and some areas immediately around those 2 towns, but not in most of Alaska.