Originally Posted by
Doug64
It is possible, but early April is pretty early for the first part of the route. We had snow in April this year, and we live in the Willamette Valley, not the mountains. You can expect rain, cold weather and snow at the higher elevations.
There was a record snowfall on Wednesday March 21st (
http://www.kptv.com/story/17209187/p...ake-up-to-snow). I cycled from Eugene to Salem the following Saturday (
http://connect.garmin.com/activity/161385290) and it was fine. I also did a three day mini-tour from Portland to Pasco, WA on April 20th/21st/22nd this year and remember cycling most other April weekends in Portland. Even this year if you were willing to be a little flexible on your dates pending local weather - that first section from Vancouver to Portland would be ok.
The issue is a little more in the mountains. You can bypass some going through Columbia River gorge but depending on route through highest passes could be an issue. Again, having a little flexibility on days and not deciding to travel in middle of a storm - I think April start can work.