I’ve found that backcountry trout (including the Bob) are not overly picky :) I think a small selection of mid-size generic dries and equal amount of mid-size nymphs would be more than adequate. Tenkara flies are “generic” in nature, not trying to imitate anything specific.
Having said that, add a couple of muddlers in too (sculpin pattern that trout, especially larger trout, find appealing).
Also there are bull trout in several of the Bob’s rivers- just keep that in mind if you hook a fish that you can’t get in or as has happened to me a couple of times, hook a cutthroat and fighting said fish and then have a bull trout grab the cutthroat!
If you want very specific info you can call a local flyshop (Kalispell or Great Falls depending on what side your trip is planned) a week or so out.
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