Update 11/16/14 – here is an interactive map I find to be quite useful.
Here is a great map from the City of Santa Clarita of all the bike trails. Some do connect to Paseos but not all. There are also plans for other trails in the future.
I will get trails for mountain biking up soon…
BikeSantaClarita 
May 5, 2012 at 22:30
Tapia Canyon is private property and a private road. Bikers are not welcome!
January 26, 2013 at 22:41
Shelley I have not been there but hear so much about it. Why do you say bikers are not welcome? So many riders go there.
March 1, 2013 at 15:28
How do I get the word out that we have a Santa Clarita Mountain Biking Team for High School students in the SCV. We compete in So Cal Dirt MTB events throughout Southen CA.