The Lost River Valley is an ATV enthusiast’s dream. Surrounded by the tallest mountains in Idaho, the landscape is filled with mountain roads, trails, passes, and more that move through rugged yet beautiful terrain. The five ATV trails in the region surround two quaint, timeless towns with very different personalities.
The tours include:
- Mackay ATV Tour, which explores the old mining sites above the town.
- The Pahsimeroi Valley: A Little Switzerland Adventure ATV Tour
- Copper Basin: An Alpine Lakes Adventure ATV Tour
- Little Lost River Valley: An Enchanted Forest Adventure ATV Tour
- Arco Pass: Gateway to Adventure ATV Tour
Mackay, Idaho
Mackay was settled in 1880 when a mining investor, John Mackay, gave the mine’s general manager permission to plant any kind of town he wished. In a show of loyalty, he named it after him. Along with a smelter on the Lost River, Mackay also had the Oregon Short Line Railroad build a spur from Blackfoot. Shortly after its founding, the town boasted a brick schoolhouse, two major hotels, a bank, an opera house, two churches, several lodging houses, and dozens of company-owned homes. Today, Mackay is a typical western town surrounded by farms and ranches that boasts a Professional Rodeo Circuit rodeo.
Arco, Idaho
Even though it was officially incorporated in 1901 when the Oregon Short Line Railroad arrived from Blackfoot, the town began much earlier in 1860 Arco when local rancher Louis Arco established a trading post. Nearly 100 years later, in 1955, Arco became the first community in the world to be lit by electricity generated solely by nuclear power. The original National Reactor Testing Station from which the power was generated is now the Idaho National Laboratory, which drives the town’s economy.
Mackay ATV Tour
Several different types of ore to be mined were discovered here, beginning in 1884, and over the years, miners recovered 42,000 ounces of gold, 2,000,000 ounces of silver, and 62,000,000 tons of copper during the 100 years the mine was active. On this ATV tour through the historic mining district above Mackay, you’ll not only travel the winding switchbacks past historic mine structures and the remnants of the old mining operations, you’ll also be treated to stunning panoramic views of the Lost River Range and the White Knob Mountains. Reaching the top of the hill delivers even more breathtaking views. The tour is designed for ATVs and similar vehicles, with many portions of the tour not accessible to standard automobiles. Due to ongoing mining operations, some trails and interpretive sites are no longer accessible to the public, and various trails are temporarily closed from time to time.
The Green Route is accessible to all transportation modes traveling on rough-graded dirt roads.
The Blue Route is accessible to all transportation modes except low-clearance automobiles. Portions of this route are extremely steep, rough, and narrow.
The Red Route is open only to all-terrain vehicles, bicycles, motorcycles (dirt bikes), horses and hikers. It is a single-lane road with two-way traffic and no turnouts.
The Route has ten major points of interest. For more detailed information about each location, please refer to the brochure available at any of the 14 businesses at the end of this post.
- Smelter Site and Hardrock Mining Exhibit
- Aerial Tramway Tensioners and Towers
- Cossack Tunnel and Compressor Building
- Horseshoe Mine and Taylor Sawmill
- Anderson Cabin
- Ausich Cabin Site
- Cliff City Town Site
- Cliff City Cabin
- Cliff City Smelter
- Shady Railroad Trestle
The Pahsimeroi Valley: A Little Switzerland Adventure ATV Tour
The Shoshone named it the “shining waters and grove by the stream.” This ATV tour begins at the site of the 1983 Mount Borah Earthquake Fault north of Mackay and climbs over Double Springs Pass. The route then drops into the Pahsimeroi Valley, home to pioneers who arrived in the late 1880s.
As you travel the route sandwiched between the Lemhi Mountains and the Lost River Range, you’ll be treated to expansive views of Mount Borah, Leatherman Peak, and Mount Breitenbach, which are snow-capped peaks. In spring and summer, the area is covered with lush vegetation and wildflowers.
Access to the Adventure
From the center of Mackay, travel north on US Highway 93 for 22 miles to reach Doublesprings Road and the Mount Borah Historical Marker. At that intersection, turn right onto Doublesprings Road, which is also Route #116. In 2.5 miles, you’ll see the Mount Borah Earthquake Interpretive Site, a fault created by the 1983 7.3-magnitude earthquake.
Continuing on Doublesprings Road for about 8 miles takes you over Doublespring Pass to a right turn on Route # 117, toward Horse Haven Pass and the Upper Pahsimeroi. In about a mile, you’ll reach a fork in the road.
Turning left, Route #268 takes you to Carlson Lake, which is a very steep descent. Turning right on Route #117 brings you to the intersection of Bureau of Land Management Roads PS 110 and PS 120. Continuing on PS 110, which is also Pahsimeroi Road, becomes PS 188, which becomes Forest Service Road #118, which continues to another fork.
Taking the left fork, you remain on Forest Service Road #118 following the East Fork of the Pahsimeroi River, with Mount Borah, Leatherman Peak, and Mount Breitenbach looming overhead. Taking the right fork puts you on Route #267, following the West Fork of the Pahsimeroi River with the same mountain views.
Follow either of those routes back to US Highway 93 and Mackay.
Copper Basin: An Alpine Lakes Adventure ATV Tour
The remote valley, referred to as the Copper Basin, has you exploring a serene landscape with cattle grazing on rich pastures, surrounded by ponds, streams, wildflowers, deer, elk, moose, antelope, ducks, geese, and herons. The whole area spans over 500,000 acres between the Pioneer Mountains and White Knob Mountain Range at over 8,000 feet above sea level. The highlight of this tour is the Lake Creek Trail, Route #4064, an 11-mile loop that circles Round Lake, Long Lake, Big Lake, Rough Lake, and Golden Lake. Even though the route is limited to vehicles 50 inches wide or less, it winds through 5 miles of beautiful Alpine meadows, ponds, lush vegetation, and wildflowers. The trail is steep, rough, and punctuated with multiple switchbacks, but the views are wonderful, and the trout fishing is great!
Accessing the Tour
Option 1: Burma Road
From Mackay, take US Highway 93 North for approximately 10 miles to Fish Hatchery Road. Turn left and follow the route until you reach the Mackay Fish Hatchery. Turn left and continue until you reach Burma Road. Turn right and follow Burma Road #142 for approximately 6 miles to Coral Creek Summit. Continue on #142 for another 8 miles to where it ends at Big Lost River Road, #135. After #142 and #135 merge, continue about 2 miles to the Copper Basin Guard Station.
Option 2: Mackay Via Corral Canyon
From US Highway 93 in the center of Mackay, turn on Main Street, heading West, which becomes Seefried Lane and then White Knob Road/Smelter Road. Proceed on Route #207, approximately 1 mile from Route #144. Continue on #144 until you reach Route # 517. Turn right, and Route #517 becomes Route #516. Follow the route for approximately 8 miles until it intersects with Route #4070. Continue through Stewart Canyon and Corral Canyon to route #142, Burma Road. Turn left on Burma Road and continue 7 miles to the Copper Basin Guard Station. Note: The steep trail through Stewart Canyon and Corral Canyon, which traverse incredibly rugged terrain, may be closed in late spring and early fall due to snowfall.
Option 3: Trail Creek Road
Trail Creek Road intersects with US Highway 93, approximately 16 miles north of Mackay. Turn left and continue 18 miles to the intersection of Wildhorse Creek Road and Copper Basin Road, Route #135. Turn left and continue on #135 to the Copper Basin Guard Station.
Little Lost River Valley: An Enchanted Forest Adventure ATV Tour
The first European fur trappers arrived from Scotland in 1819, in what was once the home of the Lemhi and Shoshone tribes, who were family to Chief Sitting Bull. They resided in the area until 1908, when they moved to Fort Hall in Blackfoot. Captain Bonneville wrote extensively about his journey through the valley, extending for about 50 miles between 4,800 and 6,100 feet above sea level between the Lost River Range and Lemhi Mountain Range. Here, the Lost River disappears into the ground before reaching the Snake River, giving the area its name. The landscapes of the high desert and densely forested region are dotted with old mines and remnants of historic buildings from days gone by.
Experiencing the Trail
From US Highway 93, which runs through the center of Mackay, turn onto Main Street. At Leslie, turn left onto The Narrows Route/Pass Creek Road Route #122. Ultimately, the road narrows, entering a canyon with steep granite walls. In about 2 miles, you will come upon an unmarked trail to the right, which leads to a hiking trail to Hidden Mouth Cave.
Back on Pass Creek Road, you’ll continue north for 3/4 of a mile to Methodist Creek on the left and Mud Lake Canyon Route on the right, which ultimately turns into Route #4094. About 5 miles on, you’ll pass through the Enchanted Forest, which extends for several miles.
Backtracking again to Pass Creek Road, turn right and proceed north for approximately 4 miles to Pass Creek Summit. From here, a graded road descends about 7 miles to Long Lost Creek Road, Route #434. Turn left and continue to Drive Creek Reservoir, now in ruins. Leaving the reservoir ruins, continue back to Route #434 for 5 miles to Long Lost Trail Head. Enjoy the views of Massacre Mountain and 11,815-foot Castle Peak.
Returning to Mackay, follow Route #434 north to Route #119, turn right on Route #122, and continue back over the summit to the Bar Road; turn right and continue back to Mackay.
Arco Pass: Gateway to Adventure ATV Tour
Pictographs sketched into the rocks and archeological evidence, including stone tools and ancient campsites, point to people living on the land surrounding Arco Pass for over 10,000 years. The Shoshone migrated here from Pocatello to locate a good source of water and hunting grounds, and fur trappers who were part of the British North West Company and the Hudson Bay Company encountered the Blackfoot tribe when they arrived in 1820. The majestic views on this route include the 80-foot limestone King Mountain Natural Arch. Expect to see antelope, grouse, and plentiful cattle on the open range.
Experiencing the Trail
Just north of the Welcome to Arco sign, turn right on Highway Drive and continue south until turning left on 2450N. Turn left again on Arco Pass Road, Route #125. Turn right on Route #1261, left on Route #1265, left again on Route #1264, and at the parking area continue on Route #561.
When you reach the intersection of Route # 561 and Route #559, turn left to continue the Arco Pass loop on Route #559. Just prior to the intersection, there is a smaller loop road, Route #560. At the intersection, if you turn right instead of left, you will reach another entrance to the adventure off Highway 33.
Route #559 turns into Route #4305, followed by Route #559, Route #1289, Route 1290, Route #1289, and Route #1202. When you reach the end of Route #1202, going right takes you on Route #125 through Corral Canyon to the intersection of Route #1207 and Sheep Camp Road. Turning right again at Route #1207 takes you to Route #4343 and, ultimately, the Natural Arch.
Traveling left at the same intersection takes you on Route #5668, Route #566, then Route # 4270, and Route #4259, which takes you over to Route #125, which proceeds to the intersection for the 80-foot limestone King Mountain Natural Arch. Alternatively, you can proceed south, and when you reach the intersection of Route #4270 and Route #4259, Thring left again takes you to a parking lot where you can turn right on Route #1264, which becomes Route #1265 and then Route #1261, which again arrives at the interaction with Sheep Camp Road. Turn right on Route #125 to return to Arco.
Responsible Rider Checklist
- Use up-to-date travel and trail maps to ensure that you ride only in permitted areas and on designated open trails.
- Always stay on the designated routes.
- Your off-road Vehicle must display a current Idaho OHV Registration Sticker.
- Always remember to tell someone about your travel plans and destinations. Never ride alone.
- Make sure your machine is mechanically sound before starting your ride. There is no service on these routes, and cell service is limited in some areas.
- Check the local weather forecast for your route.
- Take clothing that protects all potential weather conditions.
- Ensure you have sufficient water, food, and fuel for the round-trip from and back to your destination.
- Bring a backpack of emergency items such as a first aid kit, flashlight, waterproof matches, rope or tow strap, rain gear, tire repair kit, a can of compressed air, direct or electrical tape, a GPS receiver, and preferably a cell phone.
- Never mix riding with alcohol or drugs.
- And always remember, pack it in, pack it out.
ATV Trail Map Distributors
White Knob Motel & RV Park
4255 N. US Highway 93
Mackay, ID 83251
208 588-2622
Wagon Wheel Motel & RV Park
809 W. Custer
Mackay, ID 83251
208 588-3331
Sammy’s Mini Mart
318 W. Custer
Mackay, ID 83251
208 588-3340
Scoops Corner Café
221 Main Street
Mackay, ID 83251
208 760-1998
Ivie’s Market
301 S. Main Street
Mackay, ID 83251
208 588-3361
Craters of the Moon KOA RV Park
2424 N. 300 W
Arco, ID 83213
208 527-8513 or 800 562-3408
Blackfoot Motor Sports
1615 W. Bridge Street
Blackfoot, ID 83221
208 782-1981
Lost River Adventures
4255 N. Highway 93
Mackay, ID 83251
208 588-2733 or 298 LUV-2RDE
K Squared Construction
P.O. Bop 601
Mackay, ID 83251
208 339-8925
Konnex Resources, Inc.
1009 W. Custer,
Mackay, ID 83251
21st Century Auto Sales
1051 Parkway Drive
Blackfoot, ID 83221
208 684-2121
Action Motor Sports
1355 E. Lincoln Road
Idaho Falls, ID 83401
208 522-3050
Action Cycles ‘n Sleds
2540 Addison Avenue East
Twin Falls, ID 83301
208 736-8118
Butte County Economic Development
205 W. Grand Avenue
Arco, ID. 83213
208 527-3021