 The Interstate enters Platte County at its interchange with Bear Creek Road.I-25's first population center north of Cheyenne is Chugwater, where the highway crosses over a BNSF rail line and Chugwater Creek, has an interchange with WYO 211 and WYO 313 in town, and has an interchange with WYO 321 (Ty Basin Road) north of town.Those two interchanges serve as the termini for Chugwater's I-25 Bus..