You searched for: Collection University of Michigan Herbarium Catalog Collection Remove constraint Collection: University of Michigan Herbarium Catalog Collection Place Sister Rocks 7.5' quad. North Coast. Marsh on north side of Hwy 101, 1.0 km northwest of Humboldt Road, about 2.1 km southeast of Crescent City, north-northeast side of the marsh. Remove constraint Place: Sister Rocks 7.5' quad. North Coast. Marsh on north side of Hwy 101, 1.0 km northwest of Humboldt Road, about 2.1 km southeast of Crescent City, north-northeast side of the marsh.