Are there nonstop flights from Santa Rosa (STS) to Denver (DEN)?

Yes. Southwest Airlines fly this route. Flight time is about 2h 21m.

What is the fastest connection from Santa Rosa (STS) to Denver (DEN)?

via Salt Lake City ≈ 2h 52m, via San Francisco ≈ 2h 57m, via Las Vegas ≈ 3h 2m (estimated flying time, excluding layovers).

from 15,000 JAL miles (economy, one way, based on the published award charts).

Charles M. Schulz Sonoma County Airport (STS) to Denver International Airport (DEN)・1,568 km

Nonstop flights available (1 airline). Flight time about 2h 21m. Nonstop return flights also operate.

With milesJAL 15,000 miles+ (via PHX)Economy, one way, estimate. Tap a connection for miles by cabin.

13 one-stop options, sorted by estimated flying time. Tap one to see the airlines on each leg and booking links.

Times are estimated from distance. Check schedules, frequency and availability with the airline or a booking site.