Tow vehicle- do you use GPS or just a compas and a map ?

I use garmen but verify each route on a paper map. For example I put Stockton, ca, to Death valley in December and the garmen wanted me to take Hwy 99 to hwy 120 over Tioga pass, which is closed by snow every winter, to 395. So much for that route in the winter, so I put Bakersfield as a way point and it got it right. So Verify.