From I-80 in San Francisco, take I-80 east toward Oakland. Exit #27 toward Port Costa/Crockett. Turn left on Pomona Street. Turn right onto Crockett Blvd. and right again into staging area. From I-80 in Sacramento, take I-80 west toward San Francisco. Take the Pomona Street exit at Crockett. Turn right onto Crockett Blvd. and right again into staging area. From Hwy. 4 west, take the Vallejo/Crockett exit onto Cummings Skyway. Turn right on Crockett Blvd and left into the staging area.
A: OR... From the parking lot:
Take Edwards Creek Trail to WoodRat Trail.
Woodrat to Soaring Eagle Trail. Soaring Eagle to Sugar City Trail (fun). Sugar City to Big Valley Trail. Big Valley to Chorus Frog Trail (?) to Tree Frog Trail which spits you out near Big valley again. For those who are happy to climb you can start the loop over again at the top of Sugar City Trail.
I usually do Tree frog once because the climb to get there is no joke.