Gnarly singletrack along the hillside of a ravine. Tight switchbacks with steep and loose climbs. Jumps too. The trail is unmakred and disrupted some by development.
Take SH 41 north from US 212, or south from SH 5, to Jonathan. Go to Hundredmark Rd. and the Jonathan silo. Park across the street from the Jonathan silo at the SA station. The trail starts across the HM road, going up the hill. Trail is faint.
http://www.singletracks.com/item.php?c=1&i=1734