River of Grass is a 'first-movie' (practically in quotes to make the distinction) not just in the fact that it is for Kelly Reichardt, but in tone too: the film is a loose, vaguely noir-ish tale with a more low-key beat and looking forward for when the director really takes a hold of that "mumblecore" thing years later as it's about a mother of two and a 2nd-tier Jack Nicholson character think they've accidentally killed someone and they go on the run... not really(?)
It's like the American remake of Breathless I might've wanted instead of the weak one with Richard Gere. It's a little too short to be more than a little festival experiment, but it has some good jazz, some good acting, a few genuinely weird and funny moments (some with a quirky Orthodox Jew who laughs a lot), and a final twist that seems needlessly pessimistic. I want to emphasize if you're a Reichardt fan and come to this in retrospect that it's not a bad debut, and not a great one either, though it does speak to her as having more of a sense of humor than her other films might lead one to believe.