Having never fished here before, what kind of fishing can be found in Alder Lake?

The most prolific catch would be kokanee as far as the other spieces they are mentioned here http://www.washingtonlakes.com/pierce.htm
For Kokanee I use the standard pop gear and wedding ring (I always take the trebles off and use a double gami setup for short strikes)tipped with a piece of worm.
experiment with depths and you will be into fish in no time. I usually go in the spring and summer just watch out for the water skiers and jet skis, most of them are very considerate and leave lots of room around the fishermen but there are a few who thinks its fun to see how close they can get to you.
Ramprat

Alder is good trolling Late May/June but fish are small (8-10 inches).

Went to Alder lake 2 years ago, I'll never go back too many crazys for me. Jetskis, rude water skiers, too many people.

John