Thought Scour

Target player mills two cards.
Draw a card.

Tome Scour

Woodland Chasm

({T}: Add {B} or {G}.)
Woodland Chasm enters tapped.

Counterspell

Chromatic Star

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a card.

Snow-Covered Mountain

Snow-Covered Island

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Berg Strider

When Berg Strider enters, tap target artifact or creature an opponent controls. If {S} was spent to cast this spell, that permanent doesn't untap during its controller's next untap step. ({S} is mana from a snow source.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Snow-Covered Forest

Icehide Troll

{S}{S}: Icehide Troll gets +2/+0 and gains indestructible until end of turn. Tap it. (Damage and effects that say "destroy" don't destroy it. {S} can be paid with one mana from a snow source.)

Highland Forest

({T}: Add {R} or {G}.)
Highland Forest enters tapped.

Karplusan Wolverine

Whenever Karplusan Wolverine becomes blocked, you may have it deal 1 damage to any target.

Iceberg Cancrix

Whenever another snow permanent you control enters, you may have target player mill two cards.

Rimewood Falls

({T}: Add {G} or {U}.)
Rimewood Falls enters tapped.

Boreal Druid

Rime Tender

{T}: Untap another target snow permanent.

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

Winter's Rest

Enchant creature
When Winter's Rest enters, tap enchanted creature.
As long as you control another snow permanent, enchanted creature doesn't untap during its controller's untap step.

Skred

Skred deals damage to target creature equal to the number of snow permanents you control.