The trail starts off a residential street, between two houses. There are many ways to hike the canyon, but my favorite is to stay to the left as long as the trail exists. Eventually it will drop down to the canyon floor. In a little over a mile you'll reach ribbon rock and moss grotto falls. Evidence of the blasting fiasco of 1998 is all round, but the falls are still amazing I continued up the ravine on the right, which was _very_ steep. The first trail to the left goes to to the top of moss grotto, but I passed that. The second trail to the left goes to the unforgettable Thalehaha falls lookout. You can see downtown LA and the pacific ocean to the left, the falls to the right. It was quite difficult to get there, but worth it. Next trip I'll get all the way up the ravine.
Many switchbacks are loose dirt, but otherwise KB trail is mostly rideable. Plenty of poison oak, but easily avoided if paying attention. Also pay attention to log placement to avoid wasting time missing trail as it leaves stream bed.