Every named river in the Adirondack Park — the Hudson, the Moose, the Raquette, the Sacandaga, and the rivers that drain the High Peaks.
Mill Creek drains north through the Brant Lake basin — a small, wooded feeder system that traces the eastern flank of the lake's valley before emptying into its north end. The creek runs fast in spring, slows to a trickle by August, and doesn't hold much of a fishery by Adirondack standards; most anglers work the lake itself or push deeper into the backcountry. It's the kind of water you cross on forest roads or notice from a canoe at the inlet, more corridor than destination. Check with the town clerk's office in Horicon for access easements if you're planning to explore the upper reaches.
Mill Creek runs through the southern Adirondack lowlands near Brant Lake — a small tributary system in a region better known for its lake cottages and summer camps than its moving water. The creek drains into Brant Lake from the west, passing through mixed hardwood and wetland corridors that see more deer traffic than paddlers. No formal access points, no stocking records, no trail registers — this is the kind of minor waterway that shows up on the DEC's named-water list but lives mostly as a culvert under County Route 8 and a dashed blue line on the topo. If you're looking for brook trout or a put-in, you're better off at Pharaoh Lake or the Schroon River to the west.