City of Portage issued the following announcement on Nov 1.
As temperatures begin to drop, Portage Parks & Recreation will continue to provide ample outdoor recreation opportunities. All City of Portage parks will remain open from 7 AM to 7 PM daily. During late fall, winter and early spring, park users will have access to heated restrooms at the Portage Creek Bicentennial Park (PCBP) North Trailhead (424 East Kilgore Road), PCPB Trail - Milham Entrance (910 East Milham Avenue), Celery Flats Pavilion (7335 Garden Lane), and Eliason Nature Reserve (1614 Osterhout Avenue). The restrooms at Millennium Park will be open during ice rink hours of operation. Portable restrooms will also be available at the South Westnedge Dog Park (9016 S. Westnedge), Lakeview Park (9345 Portage Road) and Oakland Drive Park (7650 Oakland Drive).
The PCBP Trail and the Northwest Portage Bikeway are plowed during the wintertime, as well as portions of the trails on Romence Road Parkway and Shaver Road Parkway, as time and equipment allow. For additional information, contact Portage Parks & Recreation at (269) 329-4522.
2021 - 2022 Heated Restrooms & Plowed Trails Map
Original source can be found here.
Source: City of Portage