Question: How many acres is the Horse Range that was established by Congress in Bighorn Canyon National Recreation Area?

Context articles: Pryor Mountains Wild Horse Range
Bighorn Lake
Ed Jenkins National Recreation Area
Bighorn Canyon National Recreation Area
Bighorn Ditch Headgate
Dryhead Country
Hole in the Rock Trail
Glen Canyon National Recreation Area
M L Ranch
Hells Canyon National Recreation Area

The Pryor Mountains Wild Horse Range is a refuge for a historically significant herd of free-roaming Mustangs, feral horses colloquially called "wild horses", located in the Pryor Mountains of Montana and Wyoming in the United States.
 The range has an area of 39650 acre and was established in 1968 along the Montana–Wyoming border as the first protected refuge dedicated exclusively for Mustangs.
 It was the second feral horse refuge in the United States.
 About a quarter of the refuge lies within the Bighorn Canyon National Recreation Area.
 A group of federal agencies, led by the Bureau of Land Management, administers the range.
Bighorn Lake is a reservoir behind Yellowtail Dam within the Bighorn Canyon National Recreation Area, located in southern Montana and northern Wyoming.
Ed Jenkins National Recreation Area, formerly proposed as Springer Mountain National Recreation Area, is a National Recreation Area in Fannin and Union counties in the U.S. state of Georgia.
 Located in Chattahoochee-Oconee National Forest, the national recreation area was established in 1991 by Public Law 102-458.
 It is administered by the U.S. Forest Service and contains approximately 23330 acre .
 Prior to its establishment the area was known as the proposed Springer Mountain National Recreation Area.
 Springer Mountain, near the center of the recreation area, is the southern terminus of the Appalachian Trail.
Bighorn Canyon National Recreation Area is a national park unit established by an act of Congress on October 15, 1966, following the construction of the Yellowtail Dam by the Bureau of Reclamation.
 It straddles the border between Wyoming and Montana.
 The dam, named after the famous Crow leader Robert Yellowtail, harnesses the waters of the Bighorn River by turning that variable watercourse into Bighorn Lake.
 The lake extends 71 mi through Wyoming and Montana, 55 mi of which lie within the national recreation area.
 About one third of the park unit is located on the Crow Indian Reservation.
 Nearly one-quarter of the Pryor Mountains Wild Horse Range lies within the Bighorn Canyon National Recreation Area.
The Bighorn Ditch Headgate, also known as the Bighorn Canal Headgate, was built starting in 1892 to provide irrigation to the Crow Indian Reservation in south central Montana.
 The headgate structure diverted water from the Bighorn River to their lands.
 It was designed by William F. Graves, and construction was carried out by Crow workers.
 The project was completed in 1904.
 Today the site is included in Bighorn Canyon National Recreation Area.
Dryhead Country is a region in Carbon County and Big Horn County in southern Montana between Bighorn Canyon and the Pryor Mountains.
 The locale was named after the piles of dry bison skulls that accumulated at the base of a local buffalo jump.
 The Dryhead region starts near the Wyoming border in Bighorn Canyon National Recreation Area and extends northward into the Crow Indian Reservation.
 Dryhead Creek drains a portion of the area, falling eastwards into Bighorn Canyon.
 The semi-arid basin is one of the most remote areas in Montana.
 The area is sparsely populated with isolated ranches.
The Hole in the Rock Trail (often hyphenated as Hole-in-the-Rock) is a historic trail running east-southeast from the town of Escalante in southern Utah in the western United States.
 The Mormon trailblazers who established this trail crossed the Colorado River and ended their journey in the town of Bluff.
 The Hole-in-the-Rock expedition established the trail in 1879.
 The trail is located within the borders of the Grand Staircase-Escalante National Monument, the adjacent Glen Canyon National Recreation Area and federal Bureau of Land Management (BLM) public land to the east of the Colorado River.
 A geologic feature called the Hole in the Rock gave the trail its name.
 A modern unpaved road called the Hole-in-the-Rock Road (BLM Road 200) closely follows this historic trail to the point where it enters the Glen Canyon National Recreation Area.
 The modern road is an important access route for visiting the Canyons of the Escalante and the Devil's Garden.
 The trail is listed on the National Register of Historic Places, being added to that list in 1982.
Glen Canyon National Recreation Area (shortened to Glen Canyon NRA or GCNRA) is a recreation and conservation unit of the National Park Service (USA) that encompasses the area around Lake Powell and lower Cataract Canyon in Utah and Arizona, covering 1,254,429 acres (5,076 km) of mostly desert.
 The recreation area borders Capitol Reef National Park and Canyonlands National Park on the north, Grand Staircase-Escalante National Monument on the west, Vermilion Cliffs National Monument and the northeasternmost reaches of Grand Canyon National Park on the southwest, and the Navajo Indian Reservation on the southeast.
The M L Ranch was established by Henry Clay Lovell and his financial backer Anthony Mason in Wyoming's Big Horn Basin in the late 1870s to the south of the present location.
 The second and final location was established farther north as a cattle line camp in 1883 to be closer to markets in Billings, Montana.
 In 1884 it became the headquarters for a ranch that reached 25000 acre in area.
 The bad winter of 1886–87 killed half the stock on the ranch, more than 10,000 head., but the M L fared better than most.
 Mason died in 1892.
 Lovell died in Oregon in 1903.
 Lovell, Wyoming was named in his memory.
 The Lovell family ran the ranch until 1909.
 In the early 1960s the ranch was purchased by the Bureau of Reclamation as part of the Bighorn Lake reservoir project.
 In 1966 the headquarters site was transferred to the National Park Service as part of Bighorn Canyon National Recreation Area.
Hells Canyon National Recreation Area is a United States National Recreation Area located on the borders of the U.S. states of Oregon and Idaho.
 The recreation area, which is managed by the United States Forest Service as part of the Wallowa-Whitman National Forest, was established by U.S. Congress in 1975 to protect the historic and archaeological values of the Hells Canyon area and the area of the Snake River between Hells Canyon Dam and the Oregon-Washington border.