I see a lot of people don't like running in Vegas. Before I lived here I hated it too. I don't run much these days but my kid does. The Vegas running scene is actually great. You obviously don't want to run in the middle of the day when it is 110 out but even when it is hot it is really nice in the morning, and pretty nice in the evening (a little warmer). It never rains. Having grown up in Seattle, which has some very nice running spots, I think I'd almost rather train in Vegas. For sure you would be on the treadmill more often in Seattle.
I think the best spot to run in Las Vegas is at Floyd Lamb Park. It is in the far north of the city. There are some places in the park where you really feel like you are somewhere in California. You can also run at Lone Mountain, not amazing but an unpaved hilly 2.2 mile loop that is great for various types of training. You can run at Red Rock if you want somewhere that you can run uphill for 4 miles straight. Lots of variety. As far as I know the only public track is Pearson Community Center, neighborhood is a bit sketchy but we use it frequently in the off season. I hear rumors of some other tracks that are easily accessible but between Pearson and our high school (open much of the time) we never need to look around.
There are also places to run down near Lake Mead, I ran there long ago when I didn't live here and remember it being nice. Some kind of old railroad trail that goes through a few tunnels. Not hard to find.
Running on the strip is dumb, you'd be better off running on the treadmill in the hotel.
One caveat, Vegas is a terrible place to have to race when you are in high school. In March it is often windy. You get a great two week window in early April, then it gets hot. By the time regionals and state comes around you better be good at running in near 100 degree heat. Most people set their PRs in CA. This year was pretty good though.
Lastly someone complained about a lack of tracks in Seattle. I haven't trained there for over 30 years but we were at Mile City this year and the sign right outside the UW track says it is open to the public pretty much all the time except for when they have practice. The old Lower Woodland Park track is still there and there is another one just across the Montlake cut from UW, the Montlake Playfield, we even did some workouts there when I ran at UW. That's 3 open tracks within warmup distance from the university. I'm sure there are many others available if you actually go look for them rather than whining.