Re: Montana visitor question
OK, getting back to the original question......
October is a superb time to fish Montana. Weather may be iffy, but the crowds will be gone for the most part.
I would strongly suggest you spend one week in Bozeman and one week in West Yellowstone.
The Firehole River in the park would be tops on my list. Because the water in the Firehole is warmed by hundreds of geothermal features, you can find hatches in progress right into winter. Standing in the river with a thermal feature on one side and a bison on the other and a feisty brown on your four weight is not to be missed.
The Gibbon River at Elk Park and Gibbon Meadows is worth a day also. Solfatara Creek, which enters the Gibbon at Norris Junction should fish well, and in October you will have it all to yourself.
The only waters that might be crowded will be the Madison just inside the park and the Gibbon from its confluence with the Madison upstream to Gibbon Falls. But there is a reason why these waters will have fishermen in October. Big browns from Hebgen lake move up to spawn in October and these are the places to be to get into really big fish.
Also, West Yellowstone gives you easy access to the upper Gallatin River. The Gallatin from the park boundary upstream in the park fifteen miles or so has easy access, few crowds and good fishing for 10"-14" rainbows, browns, and whitefish. Nymphing will work best in this cold river.
West Yellowstone, like Bozeman has lots of fly shops, and if you buy a few of their flies the will tell you what's on and what's not.
Bozeman will give you access to the lower Gallatin, with the best public access above Gallatin Gateway. Definitely inquire about Nelson's and De Puy's spring creeks and the MZ Ranch. There will be a rod fee, but it won't be outrageous.
If your budget allows, consider staying a night or two at the Gallatin River Lodge just outside Bozeman. It's not cheap, but the food and lodging are world class and guests have access to two private miles of the lower Gallatin with no rod fee.