While the South Shore of Lake Pueblo has way more miles of singletrack and receives much, much more traffic than the trails on the north side, if you've ridden everything there is to ride on the south side, the northern trails are well-worth investigating as well.
From the parking area listed here, the North Shore Marina trail heads both ways out of the parking lot. Continuing north, the trail intersects with a number of other pieces of singletrack: some marked, some not marked.
On average, this set of trails is much easier than those on the south side... ie, there are no canyons, so these trails are much more similar to Inner Limits and Outer Limits.
However, if you spend enough time riding around, you may find a section of drops and jumps that is quite entertaining and well-worth sessioning!