At the start of Montana's calving season, three families brace for the hard work, stress and pressure of the coming fight to raise herds of newborn cattle. The long, brutal winter threatens to end the season before it even begins.

The families, consumed with bringing new calves into the world, get word of an impending blizzard. Then, the exhausted cowboys are thrown into a frenzy as everyone scrambles to protect already-born calves as new ones keep coming.

Disease, hay shortage and financial hardship force the cowboys to make difficult choices that impact not only their season, but the future of their ranches and the heritage they strive to preserve.

An epic tradition comes alive when the cowboys drive their cattle to the open range using horses, dogs, trucks, lassos and helicopters. However, poor communication, unruly animals and exhaustion test relationships.

The ranchers enjoy friendship and fellowship as the community comes to help brand and vaccinate the cattle. However, harsh weather threatens to derail the day.

Fire in the Montana wilderness threatens one of the ranches and the cowboys scramble to store enough hay for the winter before rains wash them out completely. Then, it's all hands on deck when tragedy strikes one of the families.

In the wake of tragedy, one cowboy must step up or the ranch could collapse from lack of leadership. Then, the search continues for someone worthy to continue the legacy of the American cowboy.

An entire season boils down to one day as the future of the American cowboy hangs in the balance. After eight months of struggles, the families prepare to sell their calves and collect their one paycheck of the year.