I hit just over 1000 miles today as I passed through Green River, UT. That includes all of the highway mileage as well as any side trips, including grocery stores and all of the mileage in the National Parks. And exactly 1 month of biking so far. Hopefully I will be able to increase the mileage as I go along, aiming for roughly 50-80 miles a day, but right now I am probably hitting 40-50 or so, unless there are special circumstances, like the mileage in the National Parks where I have to get back outside the park to camp for the night.
And the best part, so far, no flat tires!