Coloradans love cycling, but it seems only so much.
After only one year the Tour of Colorado gran fondo series has been cancelled due to higher than expected costs and low registration numbers.

“Unfortunately we are going to have to cancel the balance of the Tour of Colorado series due to increasing costs and lower-than-expected registration rates,” the promoter, Sand Creek Sports, announced after their first event, Fountain Roubaix, in May.
Only 79 riders registered for Fountain Roubaix.

The 2019 Tour of Colorado calendar included 3 gravel/road gran fondos – Fountain (May 5), Wellington (June 11), and Victor (July 14), a Colorado Springs road time trial series May – June, and a gran fondo tour of the Colorado Rocky Mountains in August.

As of now there are no plans to bring the amateur gran fondo series back, but Sand Creek Sports is trying to put together a downtown Denver criterium as the final race in a National Series and a single-day UCI International Calendar road race in southeast Denver, both in 2020.
If at first you don’t succeed, try, try again.
GRAN FONDO CALENDAR FOR USA CANADA MEXICO