So, I got a response from each of the Representatives for District 1, but my senator has yet to respond.

Here's the deal: it don't matter if it's a car, trailer, truck, SUV, motorcycle or motorhome - the state charges $30 for the annual registration. County and local fees are added to get your final bill.

Here's what Rep. Edwards had to say:

"Before the passage of I-695, all trailers were
charged a license fee. With implementation of I-695 by the Legislature, the
fee was dropped and it basically became $3 (plus some local fees).

Last session, SSB 6814 was passed and that reinstalled the licensing fee to
$30 plus local county fees. The jump from $3 to $30 was very drastic,
especially when you add the local fees!

Sec. 7. RCW 46.16.0621 and 2000 1st sp.s. c 1 s 1 are each amended to read
as follows:
(1) License tab fees shall be thirty dollars per year for (({-
motor -})) {+ all +} vehicles(({- , regardless of year, value, make, or
model, beginning January 1, 2000 -})).
(2) For the purposes of this section, "license tab fees" are
defined as the general fees paid annually for licensing motor
vehicles(({- , including cars, sport utility vehicles, motorcycles, and
motor homes -})) {+ and trailers as defined in RCW 46.04.620 and
46.04.623.

The rationale behind this reinstatement of the $30 basic fee (plus local
fees) is that trailers should be expected to pay for maintenance of the
roads since their use also causes wear and tear on our highways.

You made a good point about a trailer being used only one or two times a
week. That is probably true in many cases, but there could be instances
when a trailer is used on a daily basis. Monitoring usage in the name of
fairness would be costly and not a good use of taxpayer money."

Please take the time to send a note to your reps, letting them know how you feel about these fees.