newbie to US cycling: when to come over

[SuffolkCindy]

Hello from England. Im new to this site and never ridden in the US. I have toured extensively in Europe but my next big adventure is the first two parts of the Great Divide. I love the look of Montana. But my question is...when to come? What time of year is best?
Thanks for your help
Cindy

[John Nelson]

From the Routes FAQ page (http://www.adventurecycling.org/routes/faq.cfm):

When is the best time to ride a specific route?
Great Divide and Great Divide Canada: early summer to mid-fall. Caution: snow can occur at any time along the route. If it is a heavy snow year, high-elevation roads in the north may not be open until late June or early July.