‘I’ll run until there’s no sea left’: the gas mask-wearing ultramarathoner circling the Salton Sea

The California landmark is shrinking, exposing a toxic lakebed that threatens neighbors. Irondad' is running 92 miles to highlight the crisis

On an otherwise desolate horizon, a black dot materialized along the dramatic shoreline of California's Salton Sea one recent Saturday afternoon. Beachgoers shielded their eyes against the midday glare and watched as the mirage became 49-year-old William Sinclair, an ultramarathon runner and activist who goes by the self-given nickname Irondad".

The runner's sudden appearance felt apocalyptic: he wore an ominous full-face gas mask to block out dust, and a pair of snowshoes strapped wing-like to his back, to traverse the area's expansive mudflats. He dressed all in black, with the exception of neon orange sneakers that were already caked in dirt from running and hiking the past 16 miles, a remote stretch of both cracked and swampy earth that very rarely sees any other human activity.