POINT REYES, Calif. — Tule elk, an indigenous California breed rescued from the brink of extinction 140 years ago, graze on one side of a wire fence, while dairy cows feed on the other side here at Point Reyes National Seashore, about 30 miles north of San Francisco.

The wild elk and the domesticated cattle appear to share the breathtaking oceanfront bluff harmoniously. But a survey by the National Park Service revealed that 250 of the elk living in a penned-off reserve — nearly half the herd that was re-established in Point Reyes in 1978 — had died between December 2012 and December 2014, most likely from drought-related starvation and thirst. The elk live in a 2,600-acre enclosure at the northern tip of the peninsula.

During the same period, two free-roaming elk herds on the south end of the peninsula, outside the reserve, grew in number from 160 to 212. Ranchers complain that these elk trample their fences, feed on drought-limited forage and drink precious water meant for milk cows.

“There are ranchers who are literally on the brink of losing their operations because of the lack of forage and the damage from the elk,” said Jeffrey Creque, who farmed at Point Reyes for 25 years and now works on agricultural ecology projects.