Here are four routes to get to Silkbush from East, West or South. Start at the lower left corner of this map where is says N-1, then proceed to R101. From there you can take one of three wine routes (WR): WR1 (to the left), WR2 and WR3. The route labeled R43 is how you get to Silkbush if you miss an important turn.
If you do not make the initial (right) turnoff to Rawsonville off of the N1, you are unable to take either the first or second route to SILKBUSH. (The N1 has relatively few on/off places and no “cloverleaf” overpasses.) Your only alternative then is the turnoff to the R43 just before the large Shell station. If you get to the traffic signal (“robot”), you have missed everything and must do a U turn.
You’re almost there! Here’s a fun video that gives you a great overview of the drive.