The driving distance is 608 miles per Map Quest. The driving time per Map Quest is 8 hours and 27 minutes.
600 miles taking I-40.
The driving distance from Dallas, TX, USA to Flagstaff, AZ, USA is 965.32mi / 1553.54km
I assume you mean Barstow, CA and not Barstow, TX. The Approx. driving time from Flagstaff, AZ to Barstow, CA is about 5.5 hours, if you take I-40.
about 500 miles
The driving distance between Phoenix, AZ and Amarillo, TX is approximately 870 miles and takes around 13-14 hours to drive without traffic.
106 miles (as the crow flies) from Guymon, OK to Amarillo, TX.
Amarillo, TX is about 60 miles north of Plainview, TX. It usually takes less than an hour to drive between the two cities.
It is 517 miles according to Google Maps.
453 miles
About 200 miles, or 2 1/2 hours.
About 475 miles by car.
The driving distance between Amarillo, TX and Flagstaff, AZ is approximately 610 miles. The driving time would be approximately 9 hours 30 minutes if you were to travel non-stop in good driving conditions. (The driving time does not take into consideration conditions which may extend trip time such as weather, road work, border crossings and rush hour traffic in urban areas.)