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.