Environmentalists in San Francisco filed a lawsuit last month over thousands of cattle in the Point Reyes National Seashore. The suit comes one year after an oyster farm was forced to shut down at the park.

Per the Marin Independent Journal, the suit, filed in U.S. District Court in San Francisco against the National Park Service, claims that cattle are causing erosion, polluting waterways with manure, harming endangered salmon, and blocking public access to the park.

Today, there are 15 families with cattle grazing on about 18,000 acres in the 71,000-acre national seashore, an area famous for its cliffs, coastal prairies and rich history dating back to Sir Francis Drake’s visit in 1579. The park service spent $50 million from 1962 to 1972 buying out all of the ranchers’ property and allowed them to stay until the death of the original owner and their spouse. However, nearly all those agreements have lapsed and park officials continue to renew leases with family heirs for five- and 10-year periods.

The plaintiffs contend park service officials are violating federal law because they intend to renew 20-year leases to the ranchers without conducting adequate environmental studies on how the cows impact the seashore’s scenic resources, including its tule elk, a native species killed off in the 1800s and re-introduced in 1978. They also argue officials have not updated their 36-year-old park management plan to consider other options, like reducing the number of ranches in the park or the size of the cattle herds.

Ranchers, on the other hand, say the tule elk have spread to some of their farms, knocking down fences, wrecking irrigation equipment and putting cows at risk of disease. They want fences built and the ability to grow row crops, bring in chickens, sheep, and goats, and set up bed-and-breakfasts on the park property.

Ranchers further contend their operations are an important part of Northern California’s coastal history. They note that when developers threatened to build subdivisions on the Point Reyes Peninsula in the 1950s, ranchers formed an alliance with the Sierra Club to convince Congress and President John F. Kennedy to establish the park in 1962.

However, supporters of the lawsuit say ranching was never mandated forever under the 1962 law, and that ranchers drive ATVs, spread manure on pastures, and have brought in no trespassing signs, trailers and waste disposal pits.

A copy of the lawsuit may be viewed here.