The most distinctive natural landmark in the Ontario-Vale area is Malheur Butte. The butte, once known as Kennedy Butte after a pioneer who homesteaded at its base, is a weathered volcanic plug that rises abruptly above the lush farmlands along the banks of the Malheur River. Malheur Butte was used by Indians as a vantage point to observe approaching wagon trains on the Oregon Trail in the 1840s. Although Malheur Butte has been inactive for millions of years, Malheur County is still alive with geothermal activity in the form of hot springs. Today, Oregon Trail Mushroom uses geothermal energy at their processing plant in Vale, and efforts are being made to further utilize this unique energy source throughout the county.