Post office in Grant (CO) Find any Post office in Grant, Colorado. Addresses, phone numbers, working hours and other information. Quick go: All categories of companies Accounting Beauty salon Establishment Finance Food General contractor Lodging Park Post office Establishment, Post office US Post Office usps.com +1 800-275-8777 50455 US Highway 285, Grant, CO 80448 Establishment, Post office US Post Office +1 303-838-9430 49542 US Highway 285, Grant, CO 80448 Establishment, Post office US Post Office +1 303-838-9430 49542 US Highway 285, Grant, CO 80448 Types of companies All categories Accounting Beauty salon Establishment Finance Food General contractor Lodging Park Post office