From Hang Gliding Wiki
Blackhawk is an unrated (but should be at least hang 4) site. You can find it on the ozreport site guide for Google Earth.
To fly there, you should:
1. Drive for a pilot experienced at the site first (post on the crestlinesoaring.org or shga.com forums to this end).
2. Scout a bailout LZ for yourself. The semi-official "bailout" is a postage stamp. It would be a great idea to spend the day before your flight cutting out and marking a decent LZ.
3. Do not fly on days where the wind might have any South, SE, or E chances. You want something with North in it.