S.J.
I have Kaiser however, if you really want a "natural" experience then you need to look outside of your coverage and go with a licensed midwife. I use Andaluz Waterbirth center. They have two locations open, one in Tualatin and one just down the hill from OHSU. They are trained to handle any emergency for Mama or Baby. They only thing they cannot do is give you pitocin or and epidural. In my opinion the water has been the best pain relief I have ever had. Take a moment to think about it. You come home from work and your back and neck are sore and hurting, you probably take a couple of aspirin and then either hop into a nice warm shower or a nice warm bath. It is the same thing for labor. The water makes a huge difference.
Kaiser will not cover the cost of the labor and delivery, but Andaluz offers great options in how to pay. They are so worth the money out of pocket. Unless you ask the midwives to they will not do a vaginal check until you are in labor. The other nice thing about Andaluz is that anytime you need to you can call your midwife and get reassurance or an emergency appointment. When you make your appointments they schedule them for an hour so you have time to talk about everything that is on your mind, even if it only fears that you are having.
In my case I am seeing a midwife within Kaiser for the blood work and ultrasound at 22 weeks and otherwise Andaluz is doing all of my prenatal care. I love Andaluz, this will be my thrid child with them and they are so worth the cost out of pocket.
Please remember that if a natural experience is what you really want then look at someone who does not regularly use interventions in any manner. You can also schedule a 'Get to know you' appointment. They will show you a waterbirth video, give you a walk through of the location you are at, and let you meet several of the midwives there. It gives you a good basis if it really is the right thing for you.
Here is their website: http://www.waterbirth.net/
Good luck. email me if you have any further questions.
S.