A daughter of William wrote that he came to Utah in 1850, but his obituary indicates he came in 1849. Further research is needed to narrow the exact year of his initial emigration and identify the name of the company he traveled with.
In the winter of 1856, he also participated in the rescue effort to bring in new emigrants stranded on the plains of Wyoming the winter of 1856 does appear in the 1850 Utah census.
William's birthday is confirmed by his diary. He mentions turning 23 years old.
In 1860, he was in California. It has not yet been determined when he returned to Utah. If he returned in 1860, it's possible that he may have traveled with the Elisha Mallory company.