From the Northeastern and Southeastern U.S. and Europe the Magpie is faster and easier to reach than any multi-day western U.S. river like the Salmon or Colorado. 
There are a number of ways of reaching the starting point including flying, driving or a combination of both.

1) Fly to Montreal which has direct flights from many large U.S. cities. Arriving in Montreal, transfer to the 2 hour flight to Sept Ile arriving the evening before and spend the night in a hotel (on your own)

2) Fly to Montreal a day early and spend the evening in Montreal. Catch the early flight up to Sept Iles the following morning to meet the group.

3) Fly to Montreal a day early and transfer to the short flight to Quebec City and spend the night in the beautiful old section of the city. Quebec City is one of the most beautiful and historical cities in North America. Catch the early flight up to Sept Iles the following morning and meet the group.
(NOTE:  All flights from Montreal to Sept Iles have a short layover in Quebec City, so a stop over in Quebec City can be arranged through Air Canada at no additional charge)

4) Fly into Montreal and rent a car and drive up to Sept Iles (8 hours). The southern route is relatively flat along the St. Lawrence River and involes taking an hour ferry.  The northern route is spectacular with an impressive, mountainous coast line. There are whale watching tours offered near Tadoussac where the Saguenay River meets the St. Lawrence River. Both drives take you past (or through) Quebc City.

5) Drive to Sept Iles from New York: 15 hours, Boston: 13 hours, Washington D.C. 23 hours, Chicago. Although it makes the drive a bit longer, it is possible to visit the spectacular Gaspe Peninsula and Nova Scotia on the drive. 

Flight times to Montreal:
New York  (1 hour)
Chicago (2 hours)
Washington D.C. : (1.5 hours)
Atlanta (2.6 hours)
Houston (2.6 hours)
Western U.S. Cities (5-6 hours)
London (6.5 to 7 hours)
Paris (7 - 7.5 hours)