Silver Creek is about 16 miles north of Ketchum. You can see the pillar from the road to the East. It's a long skin in (3+ hours). You WILL encounter snowmachines.
A good guidebook to have is Matt Leidecker's http://www.exploringsunvalley.com/
Look through it and look carefully. He has a few of the major flows of the area marked. The book doesn't reference them, but they are marked. When you get to the Lorenzo Peak page, you will see where exactly the flows are that we were on. The book is at REI last time I checked.
Hope that helps. Do you climb?