April is a transition time at Yellowstone so it’s important to know what services and roads are open at this time. Be aware that you'll likely find winter weather and temperatures in April at Yellowstone.
In April many roads in Yellowstone are still closed to vehicles. The road from the north entrance in Gardiner to the northeast entrance in Cooke City is open year round. Mid-April the West Entrance usually opens to provide access to Madison, Mammoth, Old Faithful and Norris.
In early April, there are 3 waterfalls you can access along on the northern road: – Undine Falls – Wraith Falls – Lost FallsWhen the other roads open, be sure to visit: – Firehole Falls – Gibbon Falls – Lower Falls