The hills are an anticline ridge in the Yakima Fold Belt formed by north–south compression of lava flows in the Columbia River Basalt Group.

In recent years, wineries have become an important economic driver in the region and the Horse Heaven Hills AVA was established in 2005.

North-to-south compression of flood basalts that erupted several million years ago is responsible for the uplift that created the hills.

State Route 397 travels through the foothills of the range to connect I-82 to Finley, passing to the north side of Jump Off Joe.

[6][7] The Horse Heaven Hills are located in one of the hottest parts of Washington, sharing in the same semi-arid climate that is experienced in nearby cities such as the Tri-Cities and Hermiston.

Strong winds cause extensive soil erosion on farmland, with blowing dust exceeding federal air quality standards twenty times over a ten-year period.

On hot, calm days during the summer, it is believed that air moves slowly from the north across the Tri-Cities, ponding at the base of the range.

In the two centuries following the exploration missions, the human use of the Horse Heaven Hills transitioned from mostly hunting and grazing toward the modern agriculture we see in the region today, with larger cities growing on the periphery.

[18] The Lewis and Clark Expedition came down the Snake River to the present day site of Sacajawea State Park near Pasco in the fall of 1805.

The Horse Heaven Hills are noted in their journal entry on October 16 as "a range of high Countrey which runs from S. W & N E and is on the opposite Side about 2 miles distant from the Columbia".

Impressed by the knee-high grass that fed the large bands of feral horses that roamed, he remarked "the area offers excellent forage and comparative isolation...

[26][27][28] Several million years ago, lava erupted from fissures in Oregon and Idaho creating what is known today as the Columbia River Basalt Group.

[29] North-to-south compression of the basalt group caused the Horse Heaven Hills to begin slowly uplifting around 15 million years ago.

The discharge of this massive flood was approximately 10 cubic kilometres (2.4 cu mi) per hour, which is 13 times the flow of the Amazon River.

[32] The Horse Heaven Hills served as a dam for the water as it headed down the Columbia Basin, creating Lake Lewis.

These erratics are granite, which were pushed by the ice sheet from Alberta and then were deposited by the flood downstream when the icebergs that they were embedded in became stuck on the slopes of the Horse Heaven Hills and nearby ridges and later melted.

[33][34] After passing through Wallula Gap, the water was blocked at the entrance of the Columbia River Gorge forming Lake Condon on the south side of the Horse Heaven Hills.

The soils found in the Horse Heaven Hills were influenced by the Missoula floods, as well as comprising wind-blown loess and ash from volcanic eruptions from Cascade Volcanoes to the west considered to be part of the Palouse formation.

[37] While sparsely populated, the Horse Heaven Hills have become an important region for agriculture and power generation within the state of Washington.

[38][39] In 2018, Bill Gates' asset manager Cascade Investments purchased 14,500 acres of farmland in the Horse Heaven Hills for $171 million.

[41] Irrigation from the Yakima and Columbia Rivers has recently made parts of the Horse Heaven Hills into an important agricultural region.

[43] The Horse Heaven Hills AVA, an American Viticultural Area, was established in 2005 for the benefit of the wineries in the region.

The Nine Mile Canyon Project located to the south of Kennewick and Finley covers 75 acres (30 ha) and is capable of producing 95.9 megawatts.

[48] Invasive plant species have found a place in the Horse Heaven Hills in the absence of the large number of grazers who formerly roamed the region.

Upon the arrival of horses, the Native Americans likely used them for hunting, depleting the existing game, including bison, pronghorn sheep, and elk.

They spent a short time as the main grazing animal within the hills, but horses have largely been pushed out of the range, both by removal and by farming activity.

[50] A small paleontological survey in Benton County identified numerous fossilized skeletal remains, proving prehistoric mammoths, bisons, early horses, and other animals once populated the hills.

The higher altitudes where the specimens were found indicate the now extinct animals survived the Missoula Floods that occurred toward the end of the last Ice Age.