stretch of Metro-North's network that has grade crossings, a byproduct of its existence pre-electrification. Katonah and Brewster stations are located right next to grade crossings. After North White Plains, the next station is Valhalla adjacent to the Taconic State Parkway. The double-track railroad then curves to follow the Saw Mill River Valley and the eponymous parkway. Rail and road briefly separate at Mount Kisco, but then remain close by at the last stop along the Saw Mill, Bedford Hills (although the parkway cannot be seen from the station). Past Katonah, the railroad runs between the Croton River and I-684. Golden's Bridge and Purdy's are both located very close to the interstate, although only the former can be seen from it. North of the latter, the tracks follow the river to Croton Falls, and pick up Route 22 for the first time. Putnam County After Croton Falls station, the Harlem Line runs along East Branch Reservoir and crosses into Putnam County and its rural landscape. Above Brewster station, the railroad passes through the yards at Putnam Junction to Southeast station, which was formerly known as Brewster North. This is the northern boundary of third rail electrification. North of Southeast, the line operates with a single track and uses diesel locomotives. Prior to the 2010s, the branch was not signaled, and manual block system rules were used to direct train movements; however, positive train control was installed in the late 2010s. The track finally follows its own course, away from any road or river, past the former Dykemans and abandoned Towners stations up to Patterson and into Dutchess County. Dutchess County Shortly before reaching Pawling, the line enters the Harlem Valley (which takes its name from the railroad) and begins to parallel Route 22, although not as closely as it did the roads further south. A few miles north of Pawling, the Appalachian Trail crossing has its own stop to allow thru-hikers to take a break in the city and day hikers to visit the nearby Pawling Nature Preserve. The next two stops, Harlem Valley–Wingdale and Dover Plains, are roughly apart, the longest distance between any two stops on the Harlem Line. From 1972 to 2000, Dover Plains was the last stop on the line, but then tracks remaining from the NYCRR era that had not yet been torn up were renovated and the line was extended to Tenmile River and its