Head south and pass a foot gate, continue slightly uphill, and eventually descend a rough and unmaintained trail to Pine Valley Creek.
The creek may be dry at the end of the year or a river in the spring.
This part of the loop is unmarked, so head north along the creek until you meet the Espinosa Trail.
Watch out for poison oak.
Now turn left (west), eventually climbing steeper along the wider Espinosa Trail.
Note: If it's hot, hike counterclockwise, the Espinosa Trail has some shade.
How to get here:
Along the Japatul Lyons Valley Rd, Park at the large parking, 21697 Japatul Valley Rd, Horsethief Canyon Trailhead.