Contact the Cascade grotto through the NSS entry pages, and I think the
http://www.cascadegrotto.org homepage might have a way to contact Cascade grotto as well.
There are a number of southend members, so if you send a message asking that the grotto secretary pass on your request to the grotto as a whole, it is likely that when people read your message, something could be arranged.
Washington State is one of the larger states and unavoidably, those located farther from the meeting site do spend some time getting there. But it's worth it for the fellowship, learning and caving opportunities.
When a grotto's membership is very spread out, usually the close-in people make most of the meetings, and people farther away may not make all meetings but they make enough to stay in touch, they watch the board for trips, and they share questions and knowledge and just conversation over the board. As long as you are consistent in having some level of ongoing involvement, nobody is going to say, well, that guy isn't much of a member because he's not here every time. People are realistic.
The grotto is very welcoming, so do not hesitate to make contact. The next meeting is October 21. Pizza always follows.