Southeast of Chalk River, Hwy-17 crosses the namesake river of the town of Petawawa, home since 1905 to a Canadian Forces base. You can visit the small military museums on the base, including the Garrison Petawawa Military Museums. One exhibit, the Canadian Airborne Forces Collection, traces the history of Canadian paratroopers. There’s also a riverfront beach and campground, but otherwise the area is strictly off-limits, as the numerous signs along the road warn.
The rather quaint, redbrick town of Petawawa itself is two miles north of Hwy-17 via Hwy-41, well worth the short trip through what seems like one big light-industrial park.
Wrapping around the eastern edge of Algonquin Provincial Park, Hwy-17 nears Pembroke, another timber town along the Ottawa River, north of the highway. The main sights here are the more than 30 history-themed murals painted on downtown buildings; the Champlain Trail Museum (1032 E. Pembroke St., May-Sept., C$7), with exhibits on local history; and the friendly ambience and awesome food at the Nook Crêperie Inc. (26 W. Pembroke St. W, 613/735-4800), right downtown.