History of Secondary Highway 604:
Secondary Highway 604 was a local highway in the District of Kenora that provided access between Downtown Kenora and Kenora's airport. The highway existed up until the late 1990s, when the entire route was transferred to the municipal tier. The history of Highway 604 dates back to the mid-1950s, when the Department of Highways of Ontario (DHO) introduced a series of numbered Secondary Highways throughout Northern and Eastern Ontario. Highway 604 was first designated by an Order-in-Council dated May 9, 1956. The route was first depicted on a Preliminary Route Plan prepared by the DHO in May, 1956. Originally, Highway 604 was 16 miles (26 km) in length. The highway began in Downtown Kenora, but forked into two routes northeast of Rabbit Lake. The left fork curved northwest around Black Sturgeon Lake and connected to Highway 128 (now Highway 658) near Redditt, while the right fork was a spur highway that led east towards Kenora Airport. It is believed that this short spur highway leading to the airport was initially signed as Highway 604 in 1956, but that the spur was subsequently renumbered as Highway 604A. This was apparently done to eliminate confusion amongst motorists who, upon arriving at the fork, would find that both routes leading away from the fork were signed with identical highway numbers. Even with the introduction of the Highway 604A designation, it appears that there was still confusion with the route. Ultimately, the issue was resolved in 1964, when the entire northern loop of Highway 604 was renumbered as Highway 659 and the Highway 604A spur route leading to Kenora Airport was renumbered as Highway 604. The route renumbering took place on September 1, 1964.
When Highway 604 was first established in 1956, the highway was gravel-surfaced for its entire length. The section of Highway 604 from Kenora to the Highway 604A Junction was paved with a primed bituminous surface in 1964, along with the entire length of Highway 604A leading to the airport. The balance of Highway 604 around Black Sturgeon Lake remained gravel-surfaced until after the highway renumbering in 1964, when that portion of the route became Highway 659.
Provincial jurisdiction over Highway 604 began at the eastern limits of the former Town of Kenora. The route of Highway 604 leading into Downtown Kenora via Railway Street, 10th Avenue South and Park Street was considered to be a non-assumed portion of the highway under municipal jurisdiction. A Municipal Connecting Link was designated for Highway 604 through Kenora in 1970, which followed an amended route via Railway Street, 10th Avenue South, Park Street, 9th Avenue South and 2nd Street South. Under this amended route, Highway 604 connected to Highway 17 at the intersection of 2nd Street South and 8th Avenue South. The route through Kenora was formally designated as a Municipal Connecting Link by an Order-in-Council, effective April 30, 1970. The route was amended again in 1987, when the 1970 route for Highway 604 via 2nd Street South and 9th Avenue South was superceded by the more familiar route of 8th Avenue South and Park Street. The amended route was designated as a Municipal Connecting Link by an Order-in-Council, effective September 30, 1987. Interestingly, Official Ontario Road Maps produced since the late 1960s had always indicated the 1987 8th Avenue South and Park Street route for Highway 604. The Municipal Connecting Link status of Highway 604 through Kenora was revoked by a Minister's Order dated September 18, 1997.
Jurisdiction over the provincially-owned section of Highway 604 which lay beyond the Town of Kenora's limits was transferred to the Town of Jaffray-Melick, effective March 31, 1997. Subsequently, the former Towns of Jaffray-Melick, Kenora and Keewatin amalgamated to form the new City of Kenora. As a result, the City of Kenora now maintains jurisdiction over the entire route of former Highway 604 from the Highway 17 Junction to Kenora Airport. Unless posted otherwise, the speed limit on Highway 604 is 60 km/h (35 mph). Although there are no services along Highway 604 itself, services are available along Highway 17 in Kenora.