Frenchmans coulee is what people who are sort of in-the-know call it to sound cool to the folks at REI.
Person A: "...yeah, I'm going climbing at Frenchmans coulee"
Salesperson B: "really, where's that?"
Person A: "Well it's near vantage, in fact some people call it vantage"
Salesperson B: "Cool dude. Would you like to buy some fleece gloves
PERSON C: GO BACK TO FRANCE FREEDOM HATER!!!