The Low Prairie Rose (Rosa arkansana)
Native to Manitoba Tall Grass Prairie - a perennial shrub, grows to 30 cm tall, prickly woody stems; flowers June to August, colours are pink to white, 5 petals, flat, up to 7 cm across with many stamens. Leaves are compund, 9 - 11 leaflets, alternate, smooth, toothed.
Source: “Manitoba Tall Grass Prairie, a Field Guide to an Endangered Space” by Manitoba Naturalist Society. (It’s a book, not the internet)