This is the main East to West tunnel trail. The "tunnels" have existed for years, and were recently re-opened. This trail connects Eastern Penasqiuitos to the Del Mar Mesa.
There are four river crossings and the entire trail will test your cornering and ducking skills as it winds its way through dense trees.
This is a popular trail wth many blind corners, a bell is recommended.
From this trail you can connect west to Santa Monica Ridge or turn south and head up Tunnel #4
to the Del Mar Mesa.