About 390 teens and 100 parents from Franklin County are on a three-day, 20-mile trek through shrub-steppe south of the Tri-Cities to pay homage to the pioneering trip their Mormon ancestors made to escape religious persecution. It was the first time members of the Pasco Stake and Pasco North Stake of Church of Jesus Christ of Latter-day Saints participated in a trek and it was the largest group since treks started alongside the Plymouth-area farmland in 2006.