LPS connects UPS to the top of the Porcupine Rim route.
If you're run north from UPS, the feeling of things begins to change a bit. The wavy slickrock you just experienced will be replaced with ledgy sandstone punctuated by smooth trail.
LPS gets a little closer to the rim of the canyon (if you can imagine) so its a good idea to pay attention while running this trail. The ledges and the occasional large step down make this trail a bit challenging.
LPS eventually gives way to the two track of Porcupine Rim Road and the start of one of the most famous trails in the world.