Question

why a sledge is used in snow covered areas​

Answer 1

$\boxed {\boxed{ {\blue{\bold{ \underline{✅\: Verified\:Answer}}}}}}$

Answer 2

Because the area of contact is higher in the case of sledge but lower in the case vehicles with wheels. As the area of contact is higher in the case of sledge so the pressure is low. That's why sledge is used in snow covered area.