Class 200 (Locobase 11018) 
Data from "Logging Locomotives", Record of Recent Construction #96 (Baldwin Locomotive Works, 1918), p. 36-37. See also DeGolyer, Volume 52, pp. 387+. (Thanks to Stephen Low for his 16 May 2017 email noting a typo in a Locobase reference number that mistakenly directed him to a Locobase entry describing a Norwegian locomotive.) Works number was 44106 in September 1916.
Note the superheater, which was relatively uncommon in logging locomotives. Unlike the Humbird Lumber Company engine shown in Locobase 11017, this locomotive had a bare firebox with no arch tubes. Otherwise the two were essentially identical except for the choice of fuel (coal for Humbird, oil for PS & C) and the profile of the line. Clear Lake's area of operation included curves of 18 deg and 3 1/2% grades on the main line, 30 deg and 5% on the spurs on 56-lb/yd (28-kg/m) rail.
Baldwin's record presents a confusing outline of this locomotive's initial ownership. Apparently the locomotive was bought by the Clear Lake Lumber Company, which operated the PS & C. The 200 served the Clear Lake stands until the company went bankrupt in 1926. At that point, Baldwin repossessed the 200 and sold it to the Cowlitz, Chehalis & Cascade Railway. When the 15 was retired in 1955, it was donated to the City of Chehalis. More than 25 years later, the Mt Rainier Scenic Railway's shops overhauled the 15 and put it back in service.