Are there really any real steamboats operating in the United States? Maybe in Steamboat Springs, Colorado?

Yes, on the mighty Mississippi.

http://www.steamboatnatchez.com/

There are a number of small steamboats operating, though most if not all have been converted to diesel.

Those that are a few steam driven:
Belle of Louisville:
http://www.belleoflouisville.org/

The Natchez that star_gazer noted.

The famous overnight steamboats went out of business last year, Delta Queen, Mississppi Queen (and American Queen, which ran on steam and diesel)
Per wikipedia, this is the first time since 1811 that no overnight steamboats are operating on America's rivers.
https://en.wikipedia.org/wiki/American_Queen

Julia Belle Swain in Wisconsin also cancelled their 2009 season of day-trips:
https://www.steamboats.org/steamboat-pictures/julia-belle-swain.html

The Spirit of Peoria is a stern paddle-wheeler, but not a steamboat. It does overnight trips.
https://spiritofpeoria.com

I'm sorry, I keep hitting bar by mistake before ready. busted123 is baaack! Finally, through External Links at Wiki and by looking at other links, found a wealth of info: you can see a lot at link coming up. That first one to Wiki you have. 1 shipping company said it (latest update = '07) designing 2 steamboats for the "Terribles Hotel Casino" and "St. Jo Frontier Casino."
I finally just tried http://www.steamboats.com = (that says steamboats.com) a motherlode of info. They have all types listed there, per state, in the US; minimal exploration will show you; and be sure to read what the various colors in front of the boat names actually MEAN.
I learned a "sternwheeler is launched by steam, then uses the sternwheels..." (either one at the rear or two on the sides) apparently mainly to keep going at the steamboat's always stately pace. Many are used as casinsos, more are not; they are "fun cruises" of from 30 miles to much farther, along US rivers and on lakes.
There are many actual, all-the-time steamboats, more than I'd thought there would be.
And there are steamboats (2) at Disney places in the US, yet the same name is used ("Mark Twain Steamboat") out of Hannibal, Missouri, where Twain grew up.
There are also "mock sidewheelers" -so watch out for them. There are "paddlewheelers" -which also use a steam launch- but are much more in the business of continuiing progress by wheel.
I count over 75 boats in the US that are steamboats and paddlewheelers. There are many more "stern wheelers" - meaning that wheel is on the stern (back) and much like a paddlewheeler, but a smaller wheel and smaller cross-pieces. Over 10 boats in Iowa alone are listed as "casino steamboats" and that is, indeed, what they were originally meant to be:
"...during and before Civil War [steamboats] were for passengers [before that: "cargo"]...Gamblers tested luck...girls served whiskey...piano music..." etc.
You can read this and more at steamboats.com (above, safe link) which is a terrific site. Oh and http://www.quantcast.com says 7.9k Americans go on these boats per MONTH. This was fun, though I wasted time writing each name of the State boats, by state - they mostly involve words "Dixie" "Queen" "Lady" and "Belle."