Ahtanum Food Mart in Union Gap (207 Ahtanum Rd)

It's Costco. They don't have coffee or restrooms at the station part. You have to go into the warehouse for that.

untrained employees not trained on how to do refunds after a purchase using a credit/ debit card

It's an ok station. Kind of in the ghetto, but the owners are very nice.

Best place to gas up

Open to the public, also has DEF and off road Diesel at the pump.