Background
Kurt Niler's book Presidential Skiing outlines 91 individual routes (most skiable) through the presidential range in the White Mountains..
The "Why"
The Presidentials have been called the "birthplace of extreme skiing" and offer an extensive range of gullies and skiable terrain. You don't need to live in Alaska or out West to ski steep, awe-inspiring lines and I want to do that very thing right here in New Hampshire.
The Cause: Mount Washington Avalanche Center
Mount Washington Avalanche Center (MWAC) is a partnership between the Friends of Tuckerman Ravine, the Mount Washington Avalanche Education Foundation, the Mount Washington Volunteer Ski Patrol, and the U.S. Forest Service. MWAC provides snow, weather, and avalanche information for the Presidential Range, provides resources for further education and research, and leads Search & Rescue and Ski Patrol efforts on the east side of Mt. Washington.
Personally, I have a commitment to ski for a lifetime, and that requires making safety a priority in this naturally higher-risk terrain. MWAC makes it possible for me, and others, to be better informed and to be able to make more educated and safe decisions.
Technicalities
To "complete a line" I have to descend the line from top to bottom, within reason. This definition means that many of the lines I've skied in the past on Mount Washington do not count as I did not ski them from the very top - but that just means I get to do them again!
Where skiing is possible, descending will be done with skis on my feet and hopefully even making some sweet turns along the way. There will be areas that require rappels or other forms of safely descending terrain. It is still considered a ski descent if these means are used where necessary. I'm sure some side slipping and not-so-cool-looking skiing will be required at times as well.
Sending it off cliffs or ice bulges is definitely not part of the required definition of skiing a line (refer to the statement above about skiing for a lifetime).
There are a few "technical" non-skiing lines outlined in this book. For these cases, an accent via ice climbing or mountaineering methods would count as completing the route (descending the same route not necessary). Ideally, this is done with skis on the pack and an intention of skiing another line back down :)
Upon my research there are at least 20 lines in this 91 that are very technical in nature, extremely conditions dependent, and/or have a high level of risk associated with them due to terrain traps or other features. Though doing ALL of the lines in the book safely is my overall goal, completing 70 of them would be a HUGE accomplishment in itself. I think it's important to have this sub-goal to avoid feeling pressure to go outside my own personal comfort level for an arbitrary goal.