Originally Posted by
jamawani
As a historian of the American West and a cyclist with tens of thousands of miles of riding in the West, I can say that you, like most other Brits, have little sense of the scale of the region. It would take a good three weeks to ride from Seattle to San Francisco - your proposed direction is entirely wrong because of prevailing winds. Seattle to Denver would take four weeks at the very minimum. Also, the month makes a big difference - not just "summer". June may be too early to ride certain areas - while August would be brutal in the Southwest. You might be able to ride from San Francisco directly to Denver in four weeks, but that would be a tough slog for the uninitiated - 10,000 feet of climbing in the Sierras by the 3rd or 4th day and remote riding with zero services for 80 miles at a time across the Nevada desert. Remember - less is more.
A tour starting in Seattle or Portland to Glacier NP and then down to Yellowstone NP is more doable in mid-summer.
From Jackson Hole there are flights to majro international airports.
I agree with
jamawani, especially on riding from SF to Seattle. Riding north along the coast in the summer, you'll most likely experience headwinds most of the way. While we were bicycling north to south, we've watch a number of bikers heading north, struggling against the wind while we cruised along with the wind at our backs. Sure didn't look like fun to me.