You mentioned being a bit afraid to go out on your own routes . If you think you’d enjoy Jamawani’s suggestion to make your own route then go for it. I’ve done a good bit of both and my own experience has been filled with more complications with routes of my own making. But, Most of the time that works out as part of the fun but not everyone is wired the same.

Anyway I was going to suggest just heading out from the East Coast from D.C. to CO on the EasternExpress route or from VIrginia on the TA route to CO that gives you maps and routes all ready to go tested and tried and so on and ride to Colorado. The Glenwood Springs to Reno with roll aboard service on Amtrak is about as easy as it gets. For me I would not do the Western Express the first half of August.

From Reno it’s just a hop, skip and a jump over the hill to Lake Tahoe and you’ll have your own ride with you.