Refugio State Beach Underwater Survey

Underwater Survey Participants:  Dr. Laurel Breece, Dr. Sheli Smith, Dr. William Breece, Patrick Smith, John Foster, LBCC Students: Cecelia Brothers, Lucius Martin, Cynthia Schantz, Marlo & Abdullah Thomas, Sylvia, and Christine Chan

In 2001 a team of archaeologists from Long Beach City College (LBCC), Orange Coast College, UCLA, and California State Parks surveyed the environment immediately onshore and offshore for evidence of prehistoric artifacts in an attempt to determine if the Marine Managed Area of Refugio State Park contains a submerged prehistoric archaeological site.

Over the past 20 years scuba divers have encountered stone mortars in the sandy bottom offshore of the estero at Refugio.  The most recent find occurred in May of 2000 when Ranger Danita Rodrieguez discovered a small mortar (approximately 20 centimeters in diameter) with asphalt covering the outside of the artifact.  However, this was not the first or the largest artifact discovered in the waters of the underwater park area.  At least 4 stone bowls have been recovered from the same area since the mid 1970s.  All of the artifacts are in the collection at the Santa Barbara Natural History Museum and all have been identified as mortars bases or mortars.  Two, of the stone bowls, one 13 centimeters in diameter and the other 33 centimeters in diameter were identified as basket mortar bottoms (Hudson 1976).  The largest, recovered stone mortar (60 centimeter diameter) is worn entirely through at the base (Johnson 1986).  The fact that it is worn completely through has led Archaeologist Frank Frost to hypothesize that the object enjoyed a secondary career as a stone anchor (Howarth 1986). The most recent find is the most ornate of the recovered stone bowls from underwater.  Although similar artifacts within the Santa Barbara collection display shell decoration set in an asphalt filled groove around the rim of the mortar, archaeologists recovered these finds from terrestrial sites (Johnson 2001).

The main question surrounding these four artifacts and others like them, that have been recovered from underwater, is whether or not they represent inundated archaeological sites or secondary deposition from terrestrial sites.  A survey of the literature reveals that the area around the Refugio estero has prehistorically and historically been a prime location for habitation and exploitation of the natural resources.  Three large prehistoric settlements have been archaeologically investigated in the park.

The settlement on the eastern bluff above the creek and estero produced matates and mortars.  The site dates to Oak Grove Period (Period II; 8,000-5,000 BP), an era distinguished by collecting resources (Figure 3: C) (Wallace 1978).  The sites on the western bluff and at the head of the estero date to a later period associated with the Chumash Indians (Figure 3: A & B).  The earliest artifacts from sites A & B are dated at 1,000 AD; a period when diversification of trade was abundantly obvious (Rogers 1929).  Excavations of the site at the head of the estero produced numerous stone, caulking tools, asphalt and wood suggesting that it may have been a boat building location.  In this same area steatite fragments litter the surface.  Fortunately or unfortunately, the construction of Highway 1 in the early part of the 20th century covered this site making in-depth study of the location impossible.  The third site (A) located atop the western bluff is the largest archaeological settlement site.  In 1925 a devastating earthquake knocked huge slabs of the bluff into the sea.  Part of the site was lost in the natural disaster.  Continued sloughing of the cliff face due to erosion regularly exposes archaeological artifacts.

European contact occurred for the first time in 1769 as the Franciscans and Spanish military sought out prime locations for the Manilla Galleon supply outposts.  On his way north, Father Juan Crespi visited the Cannalino Indians then inhabiting the estero and noted the location in his journal (Rogers 1929).  In 1785, a land grant was issued to Jose Francisco de Ortega for the area around the estero and inland.  The Rancho was christened Nuestra Senora Refugio.  Ortega settled on the location of the prehistoric site (Figure 3:B) at the head of the estero and began raising cattle and produce.  The rancho prospered.  In fact, it was considered so prosperous that in 1818 when the pirate Hippolyte Bouchard sailed north to raid the communities of Alta California, the rancho at Refugio was one of his three targets, along with the missions at Monterey and San Juan Capistrano (Carpenter 1985).

Agriculture sounded the death knell for the estero at Refugio, which slowly silted in.  Today, only a small creek trickles through the flat alluvial plain of the park’s campground.  The insiltation of the estero did not stop at the shore line but continued offshore slowly filling in the lagoon that is bounded by two, rocky, pincer-like reefs running out from both the western and eastern headlands toward the center of the cove.  In winter, loose sands covering the seafloor just offshore retreat to deeper water (40-100ft.).  With the warmer waters of spring and summer the sands move back inshore (0-39ft).  The rocky, underwater reefs form the boundary of the seasonal change.  All of the stone bowls found by divers were located on the inshore side of the western reef during the winter months when the sand had moved offshore leaving a hardpan sand seafloor exposed.  Throughout both seasons the bottom is relatively barren, except for the area immediately around the reefs and the occasional bed of sand dollars.  On each occasion of discovery, the bowls were found lying on the surface of the bottom and did not require excavation.  On the dive when two mortar bottoms were discovered, at the same time, they were located approximately 3 meters apart.

Although the both the western and eastern reefs would have been above water up until approximately 17,000-14,000 years ago, the mortars are not associated with the earliest archaeologically dated period (13,000-8,000 BP) (Wallace 1978 and Johnson 2001).  Archaeologically mortars date to a later period associated with collecting and diversified activities.  However, it is true that the dates for these periods are related to inland sites and the dearth of coastal sites may well reflect inundation rather than the absence of sites.

In the case of the estero at Refugio although the presence of inundated sites cannot be ruled out, the timing of the finds off-shore coupled with the fact of seasonal flooding when the estero still existed in prehistoric times and the recorded earthquake devastation of 1925, suggest that the mortars and basket mortar bases that were recovered underwater represent secondary deposition from the settlement on the western bluff and the settlement at the head of the estero. 

By April of 2001 the annual shift of sand from offshore to on-shore had already begun accelerated by an on-shore storm during the week of the survey.  The team undertook three days of systematic diving to visually survey the area immediately inshore of the western reef where stone artifacts were found.  Using compass bearing and depth as a guide dive teams covered 15-20 ft swaths, visually surveying the bottom for archaeological evidence.  None was found.

The team took the remainder of the project to visit the Santa Barbara Natural History Museum collections, as well as visually survey the park from the water and along the bluffs to get a more holistic view.  In addition, after interviewing the DPR personnel, the team set about interviewing the park visitors.  Seventeen visitors to the park were interviewed in regard to diving at the park, specifically the amount of use, area of greatest visitation underwater, and facilities at the park for diving.  The interviews revealed that divers visited both reefs, but tended to focus on one or the other.  Diving instructors preferred the western reef for training due to it proximity to the large parking lot and relatively easy approach to the water.  All divers appreciated the convenient shower facilities.  That and the adjacent campground combined to make Refugio a very popular dive site for both instructors and general divers.