DCoS *does* however go into great detail about Zebulon, who seems to have very strong ties to Ghostwalker. (Though that's never spelled out explicitly.)
Obligatory Pimping:
If you're interested in adventuring in Denver, check out the
Shadowrun Missions campaign and the January 2006 issue of
Commando Quarterly which includes an update to bring Denver to 2071 for SR4.