Actually a little north of Catecroft. Dirt/gravel parking in front of a signed trail entry labeled Catecroft. There are countless trail forks to choose from. Many ways to make loops if you wish to. Leads into into the wider Knickbocker/Omstead/etc trails area to take you as many miles as you want down into the canyon and up to Auburn etc.

Terrain is pretty easy for the immediate few miles of trail, much steeper if you go down toward the confluence. Becomes much more crowded if you go down that way too -- but you can do at least 7 mile loops without getting into the steep / crowded area.