Bayside is an unincorporated community 2.25 miles south-southeast of Arcata, at an elevation of 33 feet in Humboldt County, California. The ZIP Code is 95524, the area code is 707. The relatively large area was originally covered by large, ancient Coast Redwood trees down to what was the edge of a significantly larger Humboldt Bay at high tide. Lateā¦Bayside is an unincorporated community 2.25 miles south-southeast of Arcata, at an elevation of 33 feet in Humboldt County, California. The ZIP Code is 95524, the area code is 707. The relatively large area was originally covered by large, ancient Coast Redwood trees down to what was the edge of a significantly larger Humboldt Bay at high tide. Later, the mammoth redwoods made it the natural placement of some of the area's earliest redwood lumber operations. A rock quarry was located in the area's hills, which form the beginning of the Coast Ranges, the source of water for an early public water system for the City of Arcata. Today, Bayside provides Arcata a buffer from Eureka's northward expansion along US Route 101 and the area, with the exception of some business and public buildings, is largely rural, with homes and small ranches dotting the landscape. Second growth forests exist mostly apart from cleared lands, which show some evidence of the extensive redwood forest that once existed in the form of large stumps. Some of the area's older Victorian era houses, are still present on the Old Arcata Road, the original main road connecting Arcata to Eureka. Jacoby Creek runs alongside a road of the same name from the hills in the direction of the Bay.