McDonald Flats Boat Ramp is a single-lane concrete ramp with gravel parking located in the southwest corner of Green Mountain Reservoir near Heeney, Colorado.

This primitive launch area provides convenient water access for boaters and anglers, though it offers minimal amenities compared to larger marinas in the area.

The ramp is situated adjacent to McDonald Flats Campground, making it a practical access point for overnight visitors exploring the reservoir.