In the middle, so you at least have a few inches on each side to put something down.
But 75% of your countertop is outside of the work triangle. And is that a doorway creating a traffic path through the work triangle?
Is this a remodel? Can doors/windows change? What does the rest of the floor look like?

I was thinking the middle too. That is a full height window between the countertops that is a focal point from the entry that captures a great mountain view. It's a new build but we are pretty set on keeping the windows/doors where they are to capitalize on the views. For the same reason, we don't want the range located in the island or on the section of countertop that is below the windows because the vent hood would obstruct the views. The purpose of the prep sink in the island is to be able to face family/guests at the island seating while preparing meals. Here is the entire first floor plan:

So is that a door by the stove?
How about you move the door to the deck to the living room wall so you can have an L shaped counter? There’s just so little counter space in your work triangle, yet 10 feet or so to the right of the big sink that is useless...

There is no door by the stove, it's a window. Not sure I understand your reason to move the deck door? There will be a pantry cabinet on the right end of the counter not shelving as shown here.

I’m trying to utilize your longest wall by getting an appliance on it. I think your fridge should go where you have the pantry. Then make the full length window counter height like the others. Then you’d be cooking in front of the windows, instead of crowding yourself on the side/short end of the island.

I would make the tall window wider, and move both the range and the fridge toward the exterior, then add a side-loading pantry to the left of the fridge. Side-loading cabs make it easier to access items, than a narrow, deep pantry would. That would give you more space in front of the range, and would put the fridge a step closer to the island prep space--which I would put on the longer side of the island. If you want the other window to match the tall window in width, and you still want open shelves, they can move to the side wall.

I would also make the island less deep, to provide more space in the shared aisle, with trash on the corner, shared by all zones. Drawer bases will hold more items, and be more convenient that drawer/door cabs, if the budget will support the initial extra expense.