Conditions permitting, the park roads are planned to open at 8AM on the following days for Summer 2021. The one closest to Big Sky is the West Entrance, in West Yellowstone.
Please check the National Park Service website for current road conditions.
Every spring, biking, including e-bikes are allowed on Yellowstone National Park roads while they are still closed to motorized, public travel. Spring bicycling season usually starts by early April with no set date as designated routes are opened once they are cleared from snow. The closest route to Big Sky that is open to biking is from the West Entrance to Mammoth Hot Springs.
This is a wonderful way to explore the vastness and wildlife of the park in all tranquility while getting some exercising in as well!
Spring is the best season to view wildlife in Yellowstone. Baby animals start appearing all over the park, including grizzly and black bear cubs starting mid March, bison calves in April and elk calves later on from May to June. While bears and bison are incredibly exciting to observe, please be sure to respect wildlife, follow all park safety guidelines and keep your distance for your safety and theirs.
Bison calves tend to be born from late March through May and have a fuzzy, orange-reddish fur, earning them the nickname "red dogs". The bison calves are able to keep up with their mothers just a couple hours after they are born and they are protected from danger by the rest of the herd surrounding them at all times. You will be able to see the herds with the red dogs in the meadows, make sure to watch from a distance as bison can get aggressive if too close.