Aliso Canyon Trail
Start the parking area at the far right end of Sage Hill Campground.
Aliso Canyon Trail begins at a large sign. It is an interperted hike, which means you can pick up a flier and stop and the markers and read about what's there. The whole hike is marked at all the decision points, so you really don't need my directions here at all.
The trail parallels the creek in the shade.
At an un-measured mile or so, there is a sign pointing the way to the Aliso Canyon Loop. You can choose to go up the hill to the upper loop, or continue along the lower trail and do the loop that way. Your choice.
If you chose to stay on the lower trail, you will follow along the creek, climbing slightly here and there. Eventually, you are directed to begin a real climb up the hill where you will meet with the junction to the upper loop part of the Aliso trail.
If you chose the upper loop trail, eventually you will find yourself at the same junction, after passing through a burned area that is really quite interesting to look at. Everything just grows right back after a fire, and the wildflowers are lovely in the spring. Both ends of the loop have great flowers, so you won't miss anything either way.
Both choices are at least a mile, if not a bit more than that. I really didn't measure it, and I think the interpretive fliers will tell you exactly. I have heard that it's about a 4.5 mile round trip.
Once you get to the place where the junction is, it really looks more like a 4-way junction. And it is. You are sitting in a little saddle in an open space, with a trail that appears to be a scramble up an impressive rock cliff toward the north. I think people from Upper Oso campground come up there for fun. To the east (east-ish, north-ish...this is Santa Barbara after all), the trail will take you down into Upper Oso Campground. To the south (-ish) the trail is the upper loop trail. To the west (-ish) is the lower loop. Pick a path!
Now, you can finish the Aliso Loop however you want. Or, you can take the scramble up the cliff, or go down to Upper Oso and catch the trail to 19 Oaks, and Little Pine Mountain for a real workout.
But, if you choose to do only the loop, it's about 4.5 miles round trip.