You can reach Eden Lake (and the Manigotagan River system) by portaging from the Bird River system (at Midway Lake). Refer to the map.
Portage #1: To Kangaroo Lake
The landing is at the base of a rock ridge in the northen bay of Midway (a couple of hundred metres southish from where the creek from Kangaroo enters the bay). The trail is 500 metres long. The Kangaroo landing is in the southern tip of the lake at a flat rock.
Portage #2: To Eden Lake
The landing is at the northen end of Kangaroo in the west pointing inset. The trail is about 800 metres long. The Eden landing is a small beach. Eden is a very nice lake. From Eden, you can get back to the Bird by travelling through Bee and Wingiskus lakes. [See Bird River to Wingiskus Lake.] The Manigotagan River is navigable but shallow with possible beaver dams.