ONE OF THE ITEMS on its agenda that the Senate ought to dispose of before it begins debate on the Panama Canal treaties is the bill to expand Redwood National Park. Tempers in Northern California, where the park is located, are flaring. Eighteen of the hugh trees already inside various existing parks have been vandalized since the first of the year, 10 of them fatally. The environmentalists in the area contend that some logger cut the trees in an effort to influence Congress; the loggers contend some environmentalist did it in an effort to discredit the loggers who are resisting expansion of the park. Either way, only speedy action by Congress can remove the uncertainty that has kept that part of California in turmoil for many months.

The bill, as it has been approved by committees in both houses of Congress, is neither as expansive as those who would save the redwoods wanted or as limited as the timber industry in the area insisted it must be for them to survive. It would add 48,000 acres to the existing park at a cost of something more than $350 million. That would run the land acquistion costs for the whole park to well over half a billion dollars, and there are other expenses as well. The legislation properly authorizes federal aid and jobs to displaced loggers.

Local governments may be able to recoup some of their lost taxes from federal payments. The total price is steep, but it seems to us to be reasonable. Expansions of the park will help protect its existing trees from erosion damage and will give the Park Service a better chance to develop an area that will attract tourists for more than a quick visit.

The most recent argument the timber industry has raised against expansion of the park is that such large amounts of money would be better spent on urban parks like the Gateway recreation areas in New York City and San Francisco. While it is true that more people would use such parks, the argument has a self-serving ring to it. We don't remember such support from the industry when the urban-park concept was first advanced.

In the long run, the country can afford both parks near the big cities and those, like Redwood, in which to preserve parts of what America was like before development began. The difference is that it is now or never for Redwood. If the park is not expanded, the trees will be gone in a few years. Once gone, they cannot be reclaimed. Congress has a chance now to save another small piece of the continent for future generations.