Last year my boys and I visited a local butterfly farm:
Wings of Wonder.
It was rainy and cold the day we were there and stepping into the 80 degree, 2400 sq. ft. exhibit house was a little bit of heaven. My favorite part was seeing the care my youngest son took when a butterfly landed on the small feeding stick he had received from the owner. The farm provides a great escape in fall and winter and would make a great field trip, anytime of year, for students learning about butterflies and/or tropical rain forests.
5978 Willamette Ferry St
Independence, OR 97351
Adults - $8.50
Ages 4-10 - $6.00
Not in the Salem area?
Look here for a butterfly farm near you!