Go back to the 79, go north for a mile to the Milk Ranch TH, take Milk Ranch to Azalea Springs to Fern Hollow, left on West Mesa, cross 79 and get on Cold Springs Trail to Green Valley, north on Green Valley until Soapstone, turn right and follow back to 79, cross 79 and take CA Riding & Hiking Trail back to CG.
Get to the Sweetwater Parking lot on Hwy. 79 inside the Rancho Cuyamaca State Park.
http://www.singletracks.com/item.php?c=1&i=2810