Looks like the Gran Fondo idea is continuing to catch on in the States.

Ciclosportivo N.A. is organizing two events in Colorado this year, one in Vail in June, and one outta Boulder/Longmont in October. A third one in Steamboat appears to have been canceled, but might be back in the future.

GF Vail, June 20: http://ciclosportivo.blogspot.com/20...ondo-vail.html
(basically takes the old Coors Classic stage that is now the Copper Triangle route)

GF Boulder, October 3: http://ciclosportivo.blogspot.com/20...o-boulder.html
(heads out of Longmont, up Lefthand to the Peak-to-Peak, then back via St Vrain Canyon/Hwy 7)

The usual categories apply: Pro-Cat4, then citizens classes and start times grouped by age.

There is also a Super Corsa class, which has a $5,000 cash purse and is sort of modeled on L'Etape du Tour type events, and groups pros, Cats 1-4, and citizens together as the first start wave from the gun.
http://ciclosportivo.blogspot.com/20...upercorsa.html

There are also two L'Epoca classes for historic bikes: 1900-1945, and 1946-1990, which oughta be pretty neat.

I don't know much more, nor am I affiliated -- just a heads-up for anyone interested.
These are classic Colorado rides and the chance to tackle them as timed, quasi-races should give them a different, um, spin.