It was for a time the busiest railway route in Canada,[1] carrying both timber and wood products from today's Algonquin Provincial Park areas, as well as up to 40% of the grain traffic from the Canadian west from Depot Harbour at Parry Sound through to the St. Lawrence River valley.

The railway was built by John Rudolphus Booth, a 19th-century Canadian lumber baron and entrepreneur who owned considerable timber rights in the Algonquin area as well as a major sawmill in downtown Ottawa.

To open markets for the mill's products, he purchased Donald Macdonald's lines and formed the Canada Atlantic Railway (CAR) from Ottawa to Vermont.

Traffic was further reduced with the 1932 opening of the widened Welland Canal, which allowed lakers to bypass trans-shipping points on Georgian Bay, along with the dramatic decrease in grain prices and trade during the Great Depression.

John Egan opened logging in central Ontario in the 1840s with a string of saw and grist mills along the Ottawa River.

In 1854 a crash in red pine prices forced the entire empire into bankruptcy, and Egan turned his attention to politics.

[2] In 1867 John Rudolphus Booth purchased a 250 square mile tract of Egan's lands on the western side of today's Algonquin Park.

[3] Logging was initially carried out in areas with easy access to waterways leading to the Ottawa River, but over time these started to be used up.

This led to burgeoning business at ports on Georgian Bay for trans-shipment by rail to the east, but all of the lines in the area ran south, through Toronto, which was already heavily congested.

Although the CPR was in the process of building new lines that would eventually connect Fort William to the Ottawa area, these ran north of the lakes and did not offer convenient port facilities.

[8] The CPR started planning such a service under the charter of the Atlantic & North-West, and it was reported in 1892 that they wanted to beat Booth's line into operation.

The CPR was soon making public statements about their plans to build a parallel route to Booth's, and beat his line into service.

In 1891 about 20 miles of line had been laid from Scotia Junction to Bear Lake, a little less than half the route to Parry Sound, when the company ran out of funds for further construction.

[15] On 28 March 1893, the CPR filed plans calling for a level crossing of the OA&PS near Golden Lake, but had not yet started construction.

To aid this, the OA&PS men laid their lines right up to the B&O so they could hand-carry the rails the short distance to the far side of the road.

[10] The CPR's Atlantic & North-West beat the OA&PS to Eganville, which ran a charter to the town on 30 December 1892 and opened regular service the next month.

The A&NW was now locked out of the direct approach through the Algonquin area and would be forced along a more northerly route, closer to their Brockville & Ottawa mainline.

West of Eganville the OA&PS began a steady climb through a series of rolling hills as it progressed through the Algonquin Highlands.

While the main use for the OA&PS was freight and timber transport, its existence through the wilderness of Algonquin Park gave easy access to the area.

The CNR was unable to afford repair costs and the federal government refused to provide a subsidy, thus ending through traffic for the railway.

Service continued on either side of the split, but from this point traffic declined and by the end of the 1940s only a few passenger trains were running to the lodges in Algonquin Park.

Only a short portion of the OA&PS remains in use, between Arnprior and a diamond junction with the CN mainlines just east of Ottawa.

This services hikers, all-terrain vehicles, bicycles, and horseback riding in summer, and snowmobiles and dog-sled teams in winter.

Parts of the rail bed in Algonquin Provincial park have been utilized as hiking and biking trail and vehicular access to leased properties near the parkway corridor.

The line was routed around the western side of downtown Arnprior, and crossed the Brockville and Ottawa Railway on the town's northern edge.

To this point the railway ran in the floodplains of the Ottawa or Bonnechere River, where the land is quite flat and the line is fairly straight.