South Dakota’s groundhog records concentrate along the Missouri River corridor, around Lake Oahe, Lake Sharpe, and the Missouri National Recreational River, right where wide reservoirs and river-bottom woodland split the state’s eastern and western halves. That mix of open grassy ground next to woodland edge and brushy cover is exactly the setting a groundhog needs for grazing and for a burrow entrance close by.
A groundhog digs an extensive burrow system with multiple entrances and separate chambers for sleeping, raising young, and waste, and it’s a genuine hibernator, unlike most of South Dakota’s other ground squirrels. It spends the growing season grazing grasses, clover, and garden plants to build up fat before sealing itself in for winter.
South Dakota’s records climb from March, peak in May and June, and taper off by September, matching an active season bounded by hibernation on either end. NatureServe ranks the species S4, apparently secure, in the state.
