This is my favorite “urban” canyon. I’ve used the canyon on many long rides to get from one end to the other, and beyond. This canyon widely varies in feel and quality. There are two main trails, one on either side of the canyon. They are connected by crossings, all of which are well signed. Some are subject to closure due to washout or flooding. The western half of the northern trail is mostly singletrack. Near the middle, there are some low hills, with some short technical sections. Be aware this canyon is used by hikers as well, so these narrow portions can be tricky when they are around. The south trail is mostly dirt road, with some singletrack sections available to bypass some of the rockiest portions of the road. Beyond the main canyon, the north side of the canyon has many connections to other areas to ride, mostly in the Del Mar Mesa area, with one spur heading off towards Black Mountain. The City of San Diego has a decent map of the main canyon, which is posted at many places in the canyon. I recommend spending at least half a day exploring the canyon for the first time. With all the options available, you never know what sort of loop you might come up with.