Red is underrepresented in our native plant species, and that's what makes scarlet gilia so unique. The vivid red trumpet-shaped flowers are attractive to hummingbirds, and I'd recommend planting it for that reason alone. It's a suprising pop of color that works well as a specimen planting, and is very drought tolerant.
Scarlet gilia likes sun and dry rocky soil. It does especially well on slopes. In the garden it's fine with richer soil as long as it's well-drained, and in fact garden-grown gilias tend to get kind of massive (compared to their wild siblings).
Here's the thing about gilia though: it's a biennial, meaning it lives two years. The first year is spent as a little rosette, and the flowers appear in year two. It is vital that you leave the old flower heads intact so the plant can reseed (which it does readily). The next year rosettes...the next year flowers, and so on.
Gilias look great with yellow and blue companions. Consider planting with blue flax and slender or sticky cinquefoil.