Talk about killing the golden goose.

The proposal to build a private "zip line" amusement as a way to finance the upkeep of the Koko Crater hiking trail might bring in money, it's true. But it almost certainly would diminish the very thing it's meant to protect.

The steep trail traces an old military tramway that climbs to the summit and is very popular with hikers — those who are fit enough to make the strenuous climb, anyway.

Alt-E Ventures, a California-based company, wants to give people at the top a thrill ride back down at $20 a pop. Potential riders may find both that price and the exertion of the climb too daunting for the enterprise to make a go of it.

And even if it did, the people who love the park trail come there to get back to nature, not to have a taste of Disneyland.

Commercializing the island's public spaces is not the best way to preserve our parks, in any case. City officials should listen to longtime East O'ahu hikers. Enlisting their help in maintaining the trail would make more sense for the long term.

Thanks, Alt-E Ventures. But no thanks.