I found a list for nectar/pollen sources on the West Sound Beekeepers Association website.
http://westsoundbees.org/beekeeping_articles_plant_nectar.htm

This is from the Puget Sound Beekeepers Association:
1. Oregon Grape – April, pollen and nectar
2. Cotton Wood – April, pollen
3. Willow – April, pollen and nectar is warm… See More
4. *Maple Large Leaf – April-May, pollen and surplus nectar
5. *Poison Oak – May, nectar surplus
6. *Snowberry (Buckbrush) – May-June, surplus
7. *Vine Maple – May, surplus
8. Cherry Tree – April, nectar and mainly pollen
9. Deciduous Fruit Trees – April-May, mainly pollen
10. Mustard – March, pollen
11. Fire Weed – July-August, no pollen and variable nectar
12. Raspberry – June, surplus
13. *Blackberry – June-July, nectar and pollen
14. Thistle – June, nectar and pollen
15. *Cascara – May-June, nectar
16. Cabbage – May, pollen and nectar
17. Crimson Clover – May, pollen and nectar
18. White Clover – June-July, pollen and nectar
19. Madrene – May, nectar
20. Manzanita – May, pollen and nectar
21. Dill (oil) – July, pollen and nectar
22. *Hairy Vetch – May-June, surplusnectar