Caldera, 224 NW 13 Ave., Portland, OR 97209 (503) 937-7563. 90 acres on the shore of a cerulean blue lake formed in the cinder cone of an extinct volcano in the Cascade Mountain Range of Central Oregon. Surrounded by Deschutes National Forest. Residencies of 1-5 weeks during fall, winter, and spring. Private A-frame cottages. No fees; residents responsible for travel, food, and materials costs. Having a car while in residence is extremely helpful; nearest supermarket is 15 miles away. (visual and literary arts)