Big Hill was one of the most difficult obstacles along the 2,000-mile Oregon/California Trail. The trail crossed the Thomas Fork, north of Bear River, and climbed the steep Sheep Creek Hills. After reaching the summit, pioneers could briefly glimpse westward to the Bear River Valley below before undertaking a steep descent down Big Hill. In 1849, James Wilkins illustrated Big Hill and wrote in his diary that his party started at sunrise and was obliged to ascend and descend the mountain, calling it the steepest and longest ascent they had made on the route, and adding that although he made a sketch of the descent on the other side, clouds of dust made sketching anything but pleasant. In 1843, Theodore Talbot wrote in his trip diary that they had to cross a very high hill said to be the greatest impediment on the whole route, with an ascent that was very long and tedious and a descent still more abrupt and difficult.