That's because the UPS Ground network does not extend to Alaska.
While a shipper can ship UPS Ground to Alaska, the package is transferred to the UPS air freight network for the hop to Anchorage. Typically, this is done at the Ontario hub to make the Ontario-Anchorage flight, but I've seen packages flown from other UPS hubs (mostly Louisville, but there are flights to Anchorage from Rockford, Newark, and occasionally Portland).
If you price out a UPS Ground package to Alaska, you'll note it generally takes one extra day beyond shipping to the West Coast, and the price is significantly higher than for even a transcontinental Ground shipment. UPS knows it's going to fly and prices it accordingly (still less than 3DS, but a significant premium over normal ground shipments).
Since the UPS Ground network doesn't go to Alaska (they don't run trucks up through Canada, nor do they--unlike the USPS--contract with any over-the-ocean shipping carriers), Ground can't access USPS DDFs in Alaska directly. The closest option is the USPS NDC in Federal Way, WA, a suburb located about halfway between the ports of Seattle and Tacoma. That's the facility that all USPS Parcel Select (and other ground products) shipments go through before being containerized and loaded on the northbound Matsen (formerly Horizon Lines) steamship that departs twice a week from Tacoma. It thus makes (some level of) sense that UPS should drop SurePost packages there, because that's the last stop in the USPS network before Alaska that UPS Ground has direct access to. The only alternative would be for UPS to load those packages on a northbound aircraft and fly them to Alaska, which would quickly be a money-losing proposition for the SurePost product.
That said, I've priced out SurePost to Alaska, and it ain't cheap. It's cheaper than UPS Ground (which is--remember--flown), but it's quite a bit more than normal SurePost across the country. Likely this is because UPS is having to pay the USPS a relatively large chunk of change for each package shipped those 1,500 miles by ship--they're not getting their normal super-low rate of a buck or two that they pay when they drop off a package directly at the DDF (the post office that actually makes the final delivery to the customer). The USPS itself considers ground shipments between Washington and most of Alaska to be Zone 7--the same as a shipment from Seattle to parts of Indiana and the lower peninsula of Michigan. So UPS is paying the USPS the same to ship a package from Seattle to Anchorage as it would pay them to ship it from Seattle to Kalamazoo. Even at the Commercial Plus Plus Plus rates that UPS pays, that's well north of a buck or two.
Because of that, SurePost is generally not a very good option for shipments to Alaska. Between the revenue UPS wants to collect to cover their ground operation and the cut the USPS charges, it ends up being more expensive than just using the USPS for the full distance. From basically anywhere outside of Washington and Oregon, the USPS considers shipments to Alaska to be Zone 8 (only one zone above what they charge from Seattle). So for a shipper in Iowa or Texas or Florida or even Colorado or California, it makes sense to just send it USPS Parcel Select as the difference in charge between Zone 7 and Zone 8 is much, much less than UPS charges for the privilege of getting it from the warehouse to Seattle.
Oh, and it also takes two weeks. Boats depart Tacoma on Wednesday and Friday and take four days to get to Anchorage (it also takes a day before departure to load and a day after arrival to unload, so it's really six days in transit). So best case is that UPS drops the package off at Federal Way on Wednesday night, it's sorted overnight and put in the container on Thursday and trucked to the Port of Tacoma on Thursday night to sail on Friday with a Tuesday arrival at the dock, a Wednesday arrival at the P&DC in Anchorage and an overnight sort, and a Thursday delivery (or Friday if located elsewhere in the state). Add in three days of transit from Denver or Los Angeles to Seattle (meaning the latest a package can be dropped off at UPS to make that Wednesday drop in Federal Way is the previous Friday) and you're looking at 13 calendar days at an absolute minimum for any SurePost packages to make their way from most of the Mountain West to Anchorage. (To be fair, that's still faster than native USPS Parcel Select, since the USPS runs such an inefficient ground op that they take six days to get packages from California or Colorado to Seattle versus UPS's three.)
So, more expensive than the USPS and almost as slow? SurePost really isn't a great option for shippers. 17 years in Alaska and I never once handled or received or ever saw a SurePost package (no surprise). Worrying about SurePost taking jobs away should be pretty far down on your list of things to worry about.
(And to be honest, there's really no reason for a shipper to use USPS Parcel Select, either, given that the USPS stupidly prices Priority Mail--which does fly, on FedEx to boot, and use up tons of expensive Jet-A fuel--basically the same [and lower in some cases]. A test shipment I just priced out from California to Alaska has a 10-pound shipment at $36.70 for two-week delivery using Parcel Select. Guess how much that same package is by 3-day Priority Mail: $36.71. Anyone who ships Parcel Select in that case is kinda dumb.)
It'd be a little different if UPS did as they should do and contract with Matson to run Ground containers up to Alaska on steamships. A high-volume shipper like UPS should be able to get a 40' container up to Alaska for somewhere around a couple thousand bucks. Assuming 20,000 pounds, that's 10 cents a pound, shipped--much less than the fuel costs incurred in flying packages up. Yes, it'd add a week to transit time, but people in Alaska would be happy to wait if it meant not actually getting raked over the coals in shipping charges (or having to be told by sellers that they don't ship to Alaska). And, hey, if they did this now, they could get a leg up on FedEx! And for the priority shipments that need to take less than two weeks, there's still 3DS, 2DA, and NDA (and even 2DA isn't really that much more than current non-ground Ground prices). Then UPS could offer real, competitive Ground service to Alaska--and also competitive SurePost service. And then you might need to be worried about taking jobs away.
Also, I'm sure everyone here is a little more familiar with SurePost now that it's been around a few years, but for all the people here saying that SurePost makes no sense, remember that it confers no benefit for business address deliveries. For a shipper, the prime draw of SurePost is that it avoids the residential delivery surcharge (and, I believe, the extended delivery area surcharge as well). Yes, it sounds stupid to drive right past a delivery address on your way to the DDF to drop all the SurePost packages off, but the shipper hasn't paid for you to stop at that house, and every stop you make at a house is one less delivery you can make that day elsewhere.
Addendum: Yes, I realize this thread is old, but it's still relevant and still ranks highly in Google searches on this topic.
