This is actually the first Costco gas station in a business center that I've seen. I would say located not to far off I-15 towards the west side of Las Vegas.
Another not so busy location, no lines whatsoever, even mid-day. Maybe 4 rows of pumps. Gas price was @ $2.29 for premium (not bad at all compared to Cali)
Jumping back on the 15 freeway can be tricky though. There's a lot of construction so finding the entrance can be tough, ended up back tracking onto another exit.
Found me a go to Costco gas while in Vegas!