Target people standing in the valley, not people interested in it
Location settings default to including anyone showing interest in a place, and few cities on earth attract more idle interest than this one.
Set every campaign to presence only. Then draw the geography around the valley itself, naming the areas you serve rather than a mileage radius from your office. Include Henderson and North Las Vegas deliberately, because they are separate cities and a sloppy setup can drop them or double count them.
Decide about Boulder City and the far edges on purpose. The valley is compact enough that most of it is a reasonable drive, but the outer runs cost you a half day, and a campaign should not quietly commit your estimator to one.
Watch the location report weekly for the first month. If clicks are arriving from states you do not work in, the setting is wrong, not the keyword.