Target the valley by community, because a radius pulls in open Mojave
A circle drawn around your office covers federal land, mountains and towns you do not serve, and you pay for every click inside it.
The developed valley is a defined shape with hard edges. A twenty mile radius from an office near the 215 will reach across open Mojave desert and out toward Boulder City, and none of that produces a managed door.
Build the targeting from the communities you actually cover. Summerlin, Centennial Hills, Spring Valley, Enterprise, Paradise, Silverado Ranch, and then Henderson and North Las Vegas as separate decisions rather than as an afterthought.
Remember that most of the developed valley sits in unincorporated Clark County, not the City of Las Vegas. Selecting the city as a target excludes a large share of your best addresses. Use community and postal targeting instead, then verify what is included.
Set location options to people in the targeted area, not people showing interest in it. Otherwise you buy clicks from anyone in the country reading about Las Vegas real estate, which in this market is a very large audience.