 The main line continued northwest from Leadore for another , following the broad valley and the Lemhi River downstream through fertile farming and ranching land to the county seat of Salmon.Salmon was the line's terminus, and by far the largest town on the G&P route, with a 1910 population of 1,434.The only branch line operated by the G&P began at Leadore and headed southeast, following the Lemhi River valley upstream about to the town of Gilmore, near the upper end of the valley.