Park at the big turnout on Cook-Underwood road, overlooking the salmon hatchery. Take the boot path down to the river. Stay on the boot path and stay to the leftish.
Totally worth the minor struggle getting down here, and the major struggle getting back out again. The "trail" descends nearly 550ft in 1/3 of mile, very easy to follow, but a real quadburner. I still cant believe kayakers go over these falls. Looks like instant death from this perspective.