The family traveled to Nauvoo, Illinois, where Peter found work as a stonemason on the temple. In the wagon train from Kirtland to Nauvoo he met a young widow, Mary Ann Weston Davis. After a short courtship they were married on 2 November 1841. To them were born eight children. When trouble developed in Nauvoo and the Saints were driven out, Peter and his sons traveled to New Diggens, Wisconsin, where they earned $800.00 in eight weeks in the lead mines. They used this money to equip the family for the long trip to the Salt Lake Valley.
They arrived in Salt Lake City on 17 September 1850, and a year later settled in Tooele. Challenges and discouragement filled the next five years. Poor soil, along with lack of water, plagues of grasshoppers, and Indian problems made survival difficult. During this time, Peter was involved in the government as county clerk and assessor.
In the spring of 1850, Brigham Young directed Peter to lead a party of men from Tooele to Cache Valley for the purpose of locating a permanent settlement. After surveying the area, the decision was made to settle the valley; and Maughan was chosen to lead the group. They arrived at what is now called Wellsville on 15 September 1850 and began the development first called Maughan's Fort. The settlement of Wellsville was soon enlarged, and other communities in the area were founded. Maughan was called as presiding bishop of Cache Valley, overseeing the wards and branches of the valley. In 1860, following directions from Brigham Young, he moved his family to Logan. He served as president of the Cache Valley Stake, as probate judge of Cache County, and as a member of the territorial legislature. He also held the rank of colonel in the Nauvoo Legion in Utah.
He took a second wife, Elizabeth Francis Preator, in the Endowment House on 8 December 1866. To them were born three children. After a vigorous and successful life, he contracted pneumonia and died on 24 April 1871. His body was buried in the Logan cemetery.