Most people think of jackets when worrying about staying dry at the mountain, but pants are the true workhorse of your outfit. They cover your boots, keep your butt dry on the lift, and take the brunt of the abuse when you eat it, so choose a pant that's up to the task like the Analog Men's Zenith Gore-Tex Pant. The two-layer Gore-Tex fabric and tons of features keep your legs happy no matter what conditions you face.
Gore-Tex is waterproof and breathable to block out wind and snow while allowing vapor to escape, so you stay dry from the outside and the inside. Fully taped seams prevent moisture from seeping in through the cracks, and boot gaiters with lace hooks keep snow out of your boots. The regular fit allows plenty of room to layer under and move comfortably in, and an internal waist adjustment helps keep your pants sitting where they should. Stretching all the way from knee to knee, the mesh-lined inseam vent quickly sheds excess heat during intense hikes or fast-paced park laps. A cuff cinch system keeps you from shredding your pant legs under your boots when you're walking through the parking lot.