Just south of the Ogden Nature Center Trailhead for the Shoreline Trail, but still well before 12th Street (or the Chevron on that road), is another trailhead tucked between some houses for Jumpoff Canyon. It has a cozy little parking lot, that leads to a pretty great trail. Still trying to figure out why it is called Jumpoff (is there a fun place to take a short gravity ending flight?), but I would probably have had to stick to the Jumpoff Canyon portion to discover why.The trail is moderate on the difficulty level, enough so that you could probably take an early intermediate on the trail, with a decent amount of climbing, and only a few tech spots and a very narrow trail for a little ways. I highly recommend this trail, especially as an after work or quick ride. It has a little bit of everything, with great views, a bit of up and down, a few tech challenges, etc.
The route we take starts at the trailhead, climbs for a bit (middle picture), then crosses the canal road, keeps climbing, then we took the Jumpoff Canyon South fork, which basically becomes a part of the Shoreline trail (pictured at top and bottom) at a certain point, and just rides along until it eventually crosses the canal road again to drop down to 12th Street. You might have one or two more forks, but I frankly can't remember them now.