Numerous trailheads and canoe portages along the trail provide access to the BWCAW. The canoe routes include well maintained portages between lakes. There are also canoe/kayak routes, many involving portages, along coastal bays and inland lakes. There are several impassable stretches of water requiring long, sometimes dangerous portages. Both regions have many navigable rivers with short portages between them. Two different portages allowed nearly continuous travel by canoe among different watersheds of the region. The trail will provide improved portages and access sites for paddling, fishing, and boating. The "Grand Portage" was developed in order to avoid numerous short portages. There is approximately of portages between three lakes. At numerous portages, corduroy roads had to be constructed. Numerous portages were upgraded to carriageways and railways due to their economic importance. During the Kievan era, trade and transport depended largely on networks of rivers and portages. Marathons are long-distance races which may include portages. The route was relatively free of obstacles to navigation, with only a few portages. The party was forced to perform multiple portages due to these fierce currents.