Kytroutbum - yes - that would have been French Cr. There are some off-roads within the loop that get you closer to the creek in the middle of the loop - but then you need to slide down canyon walls in places.

DMB - not to shy you away from the waters of the park (those waters along could keep you happily FFing for a week +) but yes - Castle Cr (below Deerfield Res.) is a great spot. From the lodge in the park - you're about a 45 minute drive.

My 2-cents (CDN) advice - as passed on to myself - pick up a copy of Steve Kinsella's book - Trout Fishing in the Black Hills. Very helpful on finding places. I picked it up at Dakota Angler & Outfitters (they were quite helpful as well).

Let us know how you do ...