The Raquette river is my prime stomping ground and it’s chock full of big fish of various species. My PB musky came out of the river, I caught it on a work and it was 43.5 inches
There is also the Massena Springs Park Boat Ramp (which has just been added to Google Maps, but may not show up just yet. "Springs Park" will get you to the right place and an arial view will display the launch. Another nearby alternative, but not on the Raquette, but on the Grasse River is the "Rte 37 Grass River Boat Ramp". (Also recently added to Google Maps)