I really hope the southern Utah points are wrong, they simply don't make sense. (Anywhere in SLC of course makes sense.)
Currently they are located around St. George and along I-70 significantly west of the Route 6 intersection.
Neither spot maximizes usefulness of the main routes through Utah.
Tesla, if you're listening, hear me out as to why you should put the first 2 southern Utah superchargers in Cedar City and Green River.
The goals are to cross Utah north south, as well as east west, and to get to key destination points (like Moab) covered.
Why St. George (where the south western dot currently is) isn't the best idea...
Quite simply, that puts the supercharger too close to Las Vegas (123 miles) and too far from SLC (303 miles). Thus, you cannot travel with N-S corridor in Utah from SLC to/from NV or CA as you cannot go from the St. George supercharger to the SLC supercharger, unless you go the route at 45mph (while most of I-15 is 75mph through Utah). Also, this is a very poor EV charging area (a vast empty space on Plugshare). Also, St. George to Green River (I'll get to Green river in a moment) is 289 miles, not reliably doable between superchargers.
For the south western Utah supercharger, Ceder City makes much more sense.
Here are the distances:
Cedar City to Las Vegas: 175 miles
Cedar City to Salt Lake City: 250 miles
Cedar City to Green River (allowing the I-15 to I-70 connection for travel between LA and Devner): 237 miles
Thus, Cedar City allows all connections to be made and travel throughout the south western part of the state. Also, Cedar City has 3 exits on I-15, each of which has a few restaurants.
As for the south eastern point, the current dot sits in the middle of nowhere, along a 70 mile stretch of I-70 that does not even have a gas station.
The south eastern supercharging station should be at Green River. One of Green River's primary functions is as a refueling station to allow crossing Utah in ICE vehicles, and would make sense for EV's as well.
Going south east from SLC, the main route is Route 6 to I-70, and Green River sits at this junction. Here are the distances:
Salt Lake City to Green River: 182 miles
Cedar City to Green River: 237 miles
Green River to Grand Junction, CO: 105 miles
Green River to Moab: 55 miles
The current dot for the south eastern Utah charging station sits about 40 miles west of the Route 6 - I-70 interchange. If there, it would pose a number of problems. If coming from SLC to Moab, you would have to drive an additional 80 miles out of the way to use the supercharger, thus adding far too much time and depleting needed charge in Moab. Also, if going from Denver to SLC, you would have to go 80 miles out of the way to the supercharger as you cannot reliably go from Grand Junction to SLC (284 miles).
Thus, is there are superchargers in Cedar City and Green River, the triangle of SLC to south western and south eastern Utah is perfect, and both the north-south and east-west crossings are doable.
Anyway, I know this isn't something non-Utahns think about often, but these are roads I drive often, so I hope they get it right. Plus, when you do road trip, and you need to cross our beautiful state in your Model S (using free clean energy!) you too will be glad if they get it right!