I've ridden over Schofield Pass to the 401- some loose and techy parts, but for the most part ridable. Start early to avoid jeep traffic. The first half of the these photos show it:
http://www.flickr.com/photos/ntsnow/sets/72157621394078436/. Once you get to 401, it's of course awesome. If you want more singletrack on your way to Marble, ride Tall Pines from Thompson Creek to Redstone. Even more would be to hit the Lorax trail, but you'd have to ask at an LBS for directions for that, as it's pretty cryptic.
If you want to go through Aspen, consider riding from Carbondale: Prince Creek -> Hay Park -> Snowmass -> Gov't Trail. I'd do Taylor Pass over Pearl (more singletrack). You could ride up Little Annie or Midnight Mine Rd and then ride all along Richmond Ridge behind Aspen Mtn instead of going up the pavement to Ashcroft and then up Express Cr.
This post by mikesee starts out with the connector from the Reudi to Aspen
http://forums.mtbr.com/showthread.php?t=410393. Page 3 shows Richmond Hill and Taylor.