The original building which eventually housed McCaul's gift shop was reportedly built by Reimund “Black Bart” Holzhey and then sold to islander Ina Watson. A postcard image of the gift shop from November 22, 197 shows the exterior of the building at ground-level. The building was eventually elevated with its distinctive long ramp and became know as the Tree House Gift Shop. At the time, Dean & Wanda Marshall are identified as the owners, selling driftwood, gifts and specimen shells.
The building is still standing as of June 2020 and is located just west of the Captiva post office on the left side of the road leading to Alison Hagerup beach park.