Yes, the Apollo 15 mission left its mark on the moon. And yes, you can still see it from orbit! In 2011, NASA's Lunar Reconnaissance Orbiter swooped down to 25 kilometers (about 15.5 miles) above the surface, which is roughly half its usual minimum altitude. This altitude is low enough to show tracks on the moon left behind by Apollo 15's rover.
The moon is not subject to the fast erosion we are used to on, say, Mars (subject to wind) or Earth (subject to wind, water, plants and other things). So these tracks will persist for eons, wilted only by micrometerorite rain and the occasional moonquake.
Incredibly, LRO caught a lot of details from the three EVAs the astronauts performed, including the site where they found the Genesis rock, and a zone where they saw basaltic lava. You can see more pictures comparing the Apollo 15 pictures with the LRO pictures at this NASA web page.
Image: In 2010, the Lunar Reconnaissance Orbiter caught sight of the Apollo 15 rover tracks from 39 years beforehand (NASA/GSFC/Arizona State University)