The park is small by the standards of British Columbia's protected areas - thirty hectares, established on 7 June 1966 - and it is not one island but a scattering. Sandy Island itself, which everybody locally calls Tree Island, carries the forest. Around it lie the Seal Islets, low humps of rock and gravel where the water breaks white on a rising wind. The largest of them is Seal Island, also known as Shack Island, a name that hints at the improvised, seasonal way people have always used this shoreline. Boaters anchor off. Kayakers land on the sand. Nobody stays very long, which is part of what keeps it worth going to.

The tidal flats between Longbeak Point and the park are the whole experience. At low water they are a landscape in their own right: ribbed sand, eelgrass lying flat and glossy, the small chaotic evidence of things that live buried. Herons work the margins with theatrical patience. The crossing is easy in the sense that it is flat and short, and dangerous in the sense that the Strait of Georgia does not negotiate. The water comes back across a wide, shallow plain faster than most people expect, and there is no high ground in between. Anyone walking out is doing arithmetic the entire way - how long out, how long back, how much margin. That calculation is the price of admission, and it is a fair one.

In 2012 the park was officially renamed Jáji7em and Kw'uhl Marine Park, restoring the K'ómoks names for the two parts of it. Jáji7em means "having trees" and belongs to Sandy Island - a plain, exact description that a thousand years of people arriving by canoe would have found immediately useful, because on this shoreline a stand of trees standing clear of the water is the landmark. Kw'uhl attaches to the Seal Islets, or possibly to Seal Island alone; its meaning is no longer recorded. The renaming did not invent anything. It simply put back on the map what the map had painted over, and the older name turns out to work exactly as a name should.

Denman Island, the 51-square-kilometre landmass whose northern tip points at the park, sits off Vancouver Island's east coast with Baynes Sound between them and Comox away to the northwest. Around 1,391 people live there year-round, reached by a cable ferry, the MV Baynes Sound Connector, running from Buckley Bay. Spanish charts recorded the island in 1791; Captain Richards attached the name Denman to it in 1860, for Rear Admiral Joseph Denman. Long before either, the Pentlatch and Tla'amin peoples lived here and called the island Punchlatt. The smallpox epidemic of 1862 devastated that population, and the survivors moved to Comox to live among the K'ómoks - which is precisely why the names now on the park are K'ómoks names, and why a place this small carries that much history.

Nothing about this park is permanent, geologically speaking. Sand spits and tidal flats are among the most mobile landforms there are, rearranged by every big southeasterly that comes up the strait. The trees on Jáji7em hold their ground because roots hold sand better than sand holds itself, which is a reasonable summary of why the island exists at all. Protecting thirty hectares of something that moves is an odd proposition, but it works: the park keeps the boats, the campfires, and the bulldozers at a distance, and lets the strait go on reshaping the place at its own pace.