How late can you leave.....
 

......from Yorktown heading to San Fran on the Trans Am / Western Express? I know most folks leave around May. Can you leave as late as July and still miss the snow issues crossing the Sierras in late September?

Go in the other direction?

probably depends on how many miles you plan on riding every day, no?

Very unlikely to have snow in September in the Sierras.

Climate has changed significantly since November 1846, when the Donner Wagons crossed the Sierras..
http://en.wikipedia.org/wiki/Donner_Party
California , Often in Drought Mode, Now, may not get Snow Fall in the Sierras to meet their needs next year .

2:15?

The facilities and campgrounds in Yellowstone might be the limiting factor. Most of them close Labor Day weekend or by the middle of September. If you're doing the 50 miles a day that seem average, you could leave as late as the first of July and not have to sleep with the wolves and bears in the back country. :)

I would be more worried about the heat.
You will be roasting in Virginia, toasting in Kentucky,
Broasting in Missouri, and just plain burning up in Kansas.

Eastern Colorado will feel like purgatory, but the Rockies will provide relief -
Until you hit southern Utah and Nevada.
Where the oven will take over again.

Late September in the Sierras might have nothing more than a cool, damp snap.

PS - A mid-July departure date is ideal for a trip from the Pacific Northwest eastwards and southeastwards.
A ten-week ride would put you on the east coast at the end of September - not too chilly, yet.
But your days will be getting shorter every day - especially after Labor Day.

If this is for next year, why not consider west-to-east?
The Northern Tier is spectacular - but really demanding by the third day.
You will encounter lots of westbound riders if you choose the Trans Am.
The Lewis & Clark makes for a moderate start to a trip heading east towards Missoula.

Don't know your riding style or mileage per day.
Or how much time you have to do this - I'm guessing 10 weeks.
You can do the entire Trans Am in 10 weeks -
Or you can combine sections of different routes plus your own -
And come up with a route that is no longer than the TA & Western Express.

Hah! Advice, interspersed with references to a cannibalistic starvation event.

Thanks everyone, but looking forward to riding towards something I have not seen before. Going east to west. Looking at a July departure as a Bithday present to myself. Since I am already in Va, it is an easy ride out my front door. Looking at the TA / Western Express or a trip down the ECG to Fl and picking up the ST heading west to AZ..., then north to the Western Express to San Fran. I have never seen the big ditch and have had that on the bucket list also.

That WAY too late!

Maybe Ill run into u on my way home, though i plan on modifying the Trans Am alittle bit.

Some food for thought on that...

It is much easier to work out air travel at the start of a long tour than at the end. A flexible schedule is a joy and being locked in to a return flight time and date can kill that. I find that it is easy to plan when I will leave for a trip, but not so easy to predict when I will finish one.

I find it a joy to just ride out of an airport and head toward home. It is really cool to have friends and family meet you at the end of the tour. I'd advise considering flying out and riding toward home. I have found that for me that works out much better for those reasons and lots of others. There would have to be a compelling reason for me to go the other way.

Do what works for you, but at least take that into consideration.