If parking at Spring Lake, a $7 day pass or Regional Parks pass is required. If parking at Annadel, a State Parks pass is required.
Rough Go is an uphill climb to get to Lake Ilsanjo. Its name is pretty well-deserved, as you'll see from all the erosion and rocks on the trail. About halfway through, there's a bench to sit on and take in the views of Santa Rosa and Bennett Valley.
It's easy to miss a sharp turn on Rough Go, and instead follow a trail parallel to it. This side-trail will lead back to Rough Go.