
Here’s an invaluable writing resource for you.
Although keep in mind that all these overland averages assume flat land. If you’re carrying a pack over a mountain range, you’re gonna go slower than if you’re carrying it across the plains. Then again, they also assume moderate rather than exemplary fitness levels–for instance, someone who’s spent the last four months through-hiking the Appalachian Trail with a 30-pound pack on their backs can do 40 mountainous miles on a hard-push day and average 18 to 20 miles on regular days, but they’re endurance athletes by then, and not your average merry-traveling-band stock (unless your merry traveling band has been traveling merrily over the mountains for a few months now :-p). Point is, while these numbers are incredibly useful for writers, you need to consider a number of factors that can affect them, and not just take the averages as gospel when you write.