It is 254 miles according to Google Maps taking this route:
203.35 miles
195.47 miles
217.05 miles
322
500
It is 240 miles according to Google Maps.
200.62 miles
2846.68 miles
917.74 miles
643.88 miles
Yuma County, AZ is 5,519 sq miles (14,294 km²).
555 miles