It could be anything from around 50 early in the morning to 100+ later in the day. You should be fine with any of those powders.
One thing you also might consider is bringing a rimfire of some sort. It's often a good idea to start shooting a town with a quieter rifle, because the nearby dogs will stay up longer. However, this depends a lot on how much (or whether) a town has been shot at. An already hard-hit town won't provide many opportunities with a rimfire, but a town that hasn't been shot at all will. And even on hard-shot town, you can often find some less spooky dogs by hiking into nearby draws where most people don't go. A rimfire's ideal for this, since you can dump a bunch of spare rounds in a shirt pocket.
I usually bring a .17 HMR, because it will reach out to 150-200 yards, but have killed a pile of PD's with the old Long Rifle over the years.
