Kerik Kouklas does a gum bi-chromate over platinum process that get's beautiful results. Very rich tones. He gives workshops, including out of his home in Placerville, CA. I took a two-day workshop from him, and it was excellent. He shows examples from a variety of photographers, compares several papers, has a good darkroom setup, and when given out of his home, has small class sizes.
I live nearby your location in Portland, and one can drive the distance to in a long day.