What mountain range in Utah was a major obstacle for the donner party?

The Donner Party faced significant challenges while traversing the Sierra Nevada mountain range in Utah. Although their most notorious struggles occurred in California, the Sierra Nevada presented difficult terrain and harsh weather conditions. The party's journey was hindered by heavy snowfall and steep elevations, leading to dire circumstances as they attempted to cross the mountains. Ultimately, these obstacles contributed to their tragic fate as they became trapped during the winter of 1846-1847.