Mica is a fictional, relatively new mining community in Arizona. While we don't get a ton of information on the town, we do know that it's in the desert, which is no surprise, considering Arizona is in the Southwest.
Not too much grows in the desert, right? And deserts are always dry. As it turns out, the Arizona desert is just about the perfect setting for the goings on at Mica High because the high school is just as dry as the ground on which it sits. The students are rather dull, and they worship a dull guy, Wayne, who thinks it's cool to be boring, disconnected, and altogether lame.
The high school landscape is downright lifeless until Stargirl shows up on the scene with her colorful outfits, quirky songs, and general joyfulness. Think of her as a rainstorm, who brings a much-needed dose of water, or life, to the school.
You know what else is true of the desert? There's not a lot of critters running around. In fact, if you don't look closely, a desert seems absolutely deserted (hence the name). It's the perfect place for a lonely boy like Leo, because the desert around him highlights the isolation he feels in high school. When he is shunned along with Stargirl, Leo tells us that he feels like the silent-treatment he receives is like "a second desert imposed upon the one I already lived in, where 'Hi' was as rare as rain" (23.21).
But the desert isn't all loneliness and desolation. It's also a place where, without distractions, the characters can get in touch with something deeper. Take, for example, Stargirl's enchanted place. When she and Leo visit there, he tells us, "The place couldn't have been more ordinary. The only notable presence was a tall, dilapidated saguaro, a bundle of sticks, in worse shape than Archie's Señor. The rest was gray scrub and tumbleweed and a few prickly pears" (17.67).
That might not sound like much, but for Stargirl, it's the perfect place to connect with nature. She tells Leo, "The earth is speaking to us, but we can't hear because of all the racket our senses are making" (17.85). It's only when she gets outside of town, and away from the hustle and bustle of Mica High that Stargirl can get it touch with what's really important: the deeper nature that connects us all. Without the distractions of their everyday lives, she and Leo can experience some of what nature has to offer.
The name Mica may hold some significance, too. Mica is a very strong mineral that remains stable when exposed to things like electricity, light, and even moisture. Stargirl brings a lot of light to Mica, which raises the question: does the town remain stable, or does it change after encountering her? Is Mica the town as sturdy as Mica the mineral?