Microplastics (MPs) are small pieces of plastic smaller than 5 mm in length. In order to distinguish between the origin of these plastic particles, MPs are classified as either primary or secondary. Primary microplastics are plastics that are purposefully manufactured to be small - including microbeads, which are used in personal care products, and plastic pellets, which are used to construct larger plastic products. Secondary microplastics form as a result of the chemical or physical breakdown of larger plastics, often creating randomly-shaped fragments and films of plastic. Microfibers are also frequently encountered in marine and freshwater environments, and are formed during the washing of clothing made of synthetic textiles. There is an ever-expanding body of scientific literature studying the impacts that microplastics have on aquatic organisms and the organisms that consume them [including humans]. However, data on the presence of microplastics in large rivers - including the Hudson River - remains scarce. As such, our hope is that this citizen-science project can help fill a critical data gap, while also engaging the public who rely on the Hudson River for leisure and recreational activities, and helping protect the plethora of aquatic species who call the Hudson home.