Yellowstone RV Park at Mack's Inn sits in a beautiful scenic area within the city of Island Park, Idaho. The area is rich in scenic beauty as well as its western history.

The name of Island Park derives from the many open places found among the dense forest of pines and the flat meadows formed by the caldera of the Island Park volcanic period. About 500,000 years ago much of what now forms the Island Park area was a large volcano that exploded with extraordinary force. Fallout from that eruption has been found as far away as Kansas. In the explosion's aftermath Island Park was left with a world class U-shaped volcanic caldera formation. The Island Park caldera measures 18 miles in width and is 23 miles long. Since that ancient time the crater has largely been filled in by lava flows from the east in Yellowstone National Park. Our RV Park lies at the base of the east-west trending Centennial Mountains (part of the Rocky Mountain Range). (See the Geology web page for RedRock Lakes National Wildlife Refuge here.)

However, the name Island Park was derived more specifically from the fact that near the present site of the Island Park Boy Scout Camp (on what was recently called the RR-Island Park Siding) is a clearing resembling an island bordered by the Buffalo River, Split Creek, Little Warm River, Tom Creek, and Chick Creek. The name "Island Park" was used by the railroad company when that area was used as a siding for loading railroad ties and cattle. The Tie Company, which was headquartered at the Island Park siding, was designated to operate a US post office with the title of "Island Park". Later the Tie Company moved its operation to the Trude Siding and the post office moved with them still carrying the "Island Park" title. Eventually, it was called the “Island Park Post Office” and generated enough publicity and popularity that the entire area soon adopted Island Park as its official name.

Early inhabitants of this region included extensions of the Shoshone tribe, such as the Snake, Bannock, Lemhi, and Tukudika (Sheepeaters). Full of wildlife and natural resources, Island Park was a popular hunting and fishing area for neighboring Montana tribes like the Crow and Flathead as well. Henry’s Lake, known today for its tremendous trout fishing, was a favorite of the American Indian tribes who set up camps along the lake’s shores. Indian artifacts can still be found along the banks. Around 1877, legendary Chief Joseph and the Nez Perce spent time at Henry’s Lake while fleeing General Howard and the US Army.

Lewis & Clark opened up this part of the country to further exploration. (They passed about 72 miles west of this area in 1805 and 1806.) Not long afterwards, the news of the richness of the land and especially lure of the beaver pelts attracted the first white hunters and trappers to the Island Park region.

In 1810, Andrew Henry (1775-1832), together with Pierre Menard, beginning in St Louis Missouri, led an exploration of the West in 1809—five years after Lewis and Clark. Henry’s group was guided on their journey into present day Montana by John Colter the famed Lewis and Clark expedition member and trapper. Trapping along the way, the men traveled south along the Snake River and in the winter of 1811 they constructed Fort Henry (near current-day St. Anthony, ID). The next thirty years would bring many more rugged and determined trappers (mountain men) to the unmapped wilderness of Idaho.

In 1818 Donald McKenzie led a party of trappers into the Snake River country where they trapped along the headwaters (Island Park region) of what is now called Henry's Fork of the Snake River. McKenzie continued his trapping in that region for many more years during which time his trappers took approximately 75,000 beaver pelts.

Between 1840 and 1870 the business of fur trapping had subsided. However, Island Park and neighboring Yellowstone were quickly becoming famous for their abundant wildlife and natural wonders. Many hunters, explorers, guides, visitors, and adventurists were attracted to the area.

Among the courageous explorers, guides, scouts, and hunters were Island Park’s first pioneer settlers. The first to do so was trapper and “Indian fighter,” Gilman Sawtell. Sawtell built his cabin on the shores of Henry’s Lake in 1868. That year, he built a rough road from his ranch to Virginia City, and five years later was instrumental in completing the road into Yellowstone via Targhee Pass to the Madison River and through the west entrance to the Lower Geyser Basin. The road was known as the Virginia City and National Park Free Wagon Road and conveniently passed by his lodge. It was the first road built into Yellowsone Park. Sawtell was described by a local newspaper as: "A stalwart, blonde, blue-eyed, jovial woodsman is he, who for years has kept a solitary ranch on the bank of Henry's lake, some sixty miles from the settlement. Half a dozen well built log houses constitute his establishment. There is a comfortable dwelling, a stable, a workshop, a storehouse for skins and game, and an ice house. Mr. Sawtelle's [sic] principal business has been spearing trout, packing them in ice, hauling them in wagons to Virginia City, and even as far as Helena, and disposing of them at handsome prices to the busy population, who haven't time to fish for themselves. A farm supplies him with vegetables and grain, the valleys afford him excellent hay, and land and water all about him swarms with game of every kind." In the 1870-80’s Sawtell caught and sold tens of thousands of pounds of fish from Henry’s Lake and shipped them by rail to markets as far away as Butte and Salt Lake City. The ranch suffered damage in 1877 when the Nez Perce passed through and again in 1878 by the Bannock. The ranch became a stage stop in 1880 when George Marshall began stage service into Yellowstone. His son Eben sold the ranch to Edwin Staley on June 18, 1896 and the area became known as Staley Springs.

Next to the Henry's Lake area came Richard W. Dick Rock (Rocky Mountain Dick), a respected scout and guide (known to run with Calamity Jane and Wild Bill Hickock). He thought Henry’s Lake a great place to hang his hat. Rock was an interesting fellow with even more interesting pets. He supplied many of the nations zoo's with local wildlife. Among his unusual collection of pets was a buffalo named “Lindsay” and a cart-pulling moose he called “Nellie Bly.” He eventually was gored by one of his "tame" pet Bison to end his career and life.

George Rea was the third settler of Island Park. He built his home in the Shotgun Valley just a few miles south of Henry’s Lake. George Rea not only operated the first cattle ranch and trout farm in Island Park, but he was a successful hunting guide. His most famous customer was President Theodore Roosevelt, whom he guided on several occasions through Island Park and the Yellowstone country. The George Rea had one of the very first private fish farms/hatcheries in the State of Idaho on his homestead in the Shotgun Valley.

One of the most prominent of these late-nineteenth century trappers was Richard "Beaver Dick" Leigh. He lived in the Snake River valley year round and did his trapping, hunting, and guiding throughout all the region adjacent to the upper Snake River valley, becoming well known for his knowledge and ability. He was introduced to the area by the Hudson Bay Company. Later he spent time in Utah and met Brigham Young who supposedly nicknamed him "Beaver Dick". Leigh was often in contact with the Shoshone and Bannock Indians and as a result he knew their languages. With this talent, the government used him as a guide for the Hayden Survey and later on as an interpreter during the Bannock War. Leigh's first wife was from the Eastern Shoshone tribe and his second wife was from the Bannock Indian tribe.

Ever so often, the Flathead Indian tribe would leave their native lands near the Three Forks country in Montana and travel upstream along the Madison River and spend time in the Island Park region. In the summer of 1840, the entire tribe traveled to Pierre's Hole (Teton Basin) in the Teton Mountains to meet the Roman Catholic missionary, Father DeSmet. The Flathead Indians had a reputation of being peace-loving, God-fearing Indians and were desirous of hearing about this white man's God. The Flathead tribe, 1600 strong and Father DeSmet in their company, took the general route back to Montana following the North Fork of the Snake River through Island Park. They were known to have camped overnight at Henry's Lake. DeSmet claimed that he inscribed a rock about 5,000 up a mountain in the Henry's Lake region with the following inscription (in Latin) - "July 23, 1840 DeSmet". It's not been found yet.

As Yellowstone’s popularity grew during the late 1800s so did the exposure of Island Park. From 1898 to 1909, many of Yellowstone National Park’s tourists made their way across the Montana border into Idaho. A stagecoach followed a trail directly through the Centennial Valley to West Yellowstone from Monida, MT. Among the many travelers who made this trek was prominent Illinois lawyer, A.S. Trude. He fell in love with the Shotgun Valley and purchased a ranch along the Snake River in 1891. He and his family became George Rea’s neighbors and steadfast friends. A.S. Trude was a true admirer of the outdoors. He was the first in the area to set forth conservation efforts for the preservation of natural wildlife habitat. One of his great contributions is still one of Island Park’s gems. Trude sold a large easement of land to the Federal Government with orders that it be flooded. His orders were followed and Island Park Reservoir was created.

In 1902, three wealthy Oregon Short Line Railroad owners and investors bought land in Island Park in order to further their ventures in livestock. The locals referred to it as the Railroad Ranch even though its official name was the Island Park Land and Cattle Company. With its stunning scenery, the ranch became a beloved retreat for its owners and their associates.

Six years later, E.H. Harriman bought a large share of the Land and Cattle Company’s holdings. The cattle ranch was extremely successful and was in operation until 1977 when 14,700 acres of it was gifted to the State of Idaho by Mr. and Mrs. Harriman. Today, Harriman State Park is known as one of Idaho’s true treasures. Nestled inside an 11,000-acre wildlife refuge, Harriman is a tranquil sanctuary for Moose, Elk, Deer, Trumpeter Swan, Sandhill Crane, and much more.

At the end of the nineteenth century, people were starting to hear of Yellowstone's rich and glorious wildlife and scenery and there existed a need for good transportation to the Park. Island Park served as a gateway for much of the transportation to the park. The Monida & Yellowstone Stage Line was formed in 1898 by Frank J. Haynes and Wm. H. Humphrey, they received a 10-year lease from Interior. They provided stage service from the UPRR depot at Monida to the park, using red Concord stages, and became known as the 'Red Line`. The route from Monida passed through Centennial Valley, now home of the Red Rock National Wildlife Refuge, past Henrys Lake, over the Continental Divide and then over Targhee Pass and then to ranches near West Yellowstone.

Following the influx of early settlers, Island Park continued to attract avid outdoorsmen throughout the 1900s. The area quickly became famous for its world-class fishing and hunting. Inns such as Island Park Lodge, Ponds Lodge, Mack’s Inn, and Phillip’s Lodge were built in order to accommodate the many travelers. All but one of these historic landmarks are still in operation

In 1916 Yellowstone Park roads were opened to automobiles. on and serve as lively meeting places for locals and tourists.

During the Great Depression Era of the early 1930s the Island Park Dam was built, employing many out-of-work people from the area. The dam made it possible to store water from the Snake River for irrigation purposes and provided Island Park with its first hydro-electric power.

Today, the mountain community of Island Park is home to nearly 400 residents, several great restaurants and pubs, a plethora of fishing/hunting guides, sportsman shops, a golf course, and rental shops. Island Park is a winter and summer paradise with a strong tourist economy. This beautiful region of Idaho is the perfect destination for outdoor recreation including camping, hiking, fishing, hunting, water sports, wildlife viewing, cross country skiing, photography, and snowmobiling. Island Park is truly one of Idaho’s premiere destinations and unique wonders.

The city of Island Park was incorporated in May 1947 to meet a state law requiring businesses that serve or sell alcoholic beverages to be within an incorporated town. The city’s government at the time drew up the city’s boundaries to include all the businesses from the Last Chance area north to the Montana border that desired licenses to serve and sell alcoholic beverages. All other areas of what is now known as the Island Park Recreational area remained in Fremont County.

Because of this, most of the city’s “main street” is U. S. 20, a major highway lined with lodges, motels, gas stations, restaurants, lounges, convenience stores, fishing and tackle shops RV parks and snowmobile and ATV rental businesses. And since almost 37 miles of U. S. 20 are in the city, the city of Island Park proudly boasts that it has the “longest Main Street in America,” varying in width from 500 to 5,000 feet! By the way, at a length of 3,365 miles, US20 is the "longest highway in America" also.

As a gateway to Yellowstone, Island Park has gained a reputation as a destination independent of the National Park as well. The area is known for its wildlife, wildflowers, majestic mountains, Henry’s Lake, the Henry’s Fork of the Snake River, the Island Park Reservoir, and many other beautiful natural features. The Caribou-Targhee National Forest encompasses most of the Island Park Recreation Area and several miles of the city. The forest is mostly lodgepole pines, with several areas of old growth Douglas fir and spruce trees that are habitat for a variety of songbirds, raptors, large and small mammals, and wildflowers. The area is known for its excellent fishing, hunting, bird watching, photography, boating, camping, hiking, ATV riding, mountain biking, snowmobiling, and cross- country skiing.

There are two state parks in this area ­ Harriman State Park and Henry’s Lake State Park, as well as a newly established National Water Trail ­ a stretch of the Henry’s Fork from Big Springs to Mack’s Inn. The Mesa Falls Recreation Area includes a visitor’s center in a historic lodge near the Upper Mesa Falls, Lower Mesa Falls, trails, and picnic areas. The Big Springs area is home to the Johnny Sack Cabin and Waterwheel, which are on the National Register of Historic Places. Johnny Sack, a German cabinet maker, came to the United States in his 20's. In 1929, he leased a small tract of land at Big Springs from the Forest Service. The cabin was started in 1932 and completed three years later. Even though he was a bachelor all his life, he had many friends and visitors. Consequently, he added on to the house over the years. The shapes and overall character of the cabin seem to derive from the prevailing bungalow mode of the period of construction (1932-1934) rather than from German models which may have been known to its immigrant builder, Johnny Sack. The roof pitch, extended eaves, exposed rafters, and chopped gables are all typical bungalow features which can be seen in most small towns in Idaho.

What makes the craftsmanship of Johnny Sack unique is the use of bark in the details of the house and his furniture. Through careful preparation of the lumber, the bark remains on the wood, providing a creative texture and color to the trim of windows, wall panels, ceiling lamps, chairs, desks, beds, and other wooden items.

John Sack was only 4 feet 11 inches tall. While most of the house has typical ceilings, his work area in the basement reflects his small statue.

Also in the Island Park area are three historic byways ­ the Fort Henry Historic Byway, the Lost Gold Trails Loop, and the Nez Perce Historic Trail. This trail route honors the heroic and poignant attempt by the Nez Perce Indians to escape capture by the U.S. Army. In 1877, the Nez Perce were forced to leave their ancestral homelands and move to a reservation east of Lewiston, Idaho. During this journey, hostilities broke out between white settlers and some groups of the Nez Perce. The U.S. Army was called in. The resisting bands headed east, crossed the Rocky Mountains, and hoped to find refuge in Canada.

The official Nez Perce trail stretches approximately 1,170 miles, starting at Wallowa Lake in eastern Oregon. It crosses central Idaho, paralleling the Clearwater and Lochsa Rivers, enters Montana at Lolo Pass, and then runs south through the Bitterroot and Big Hole Valleys. It crosses Bannock Pass and re-enters Idaho near Leadore. It then runs south through the Birch Creek and Lemhi Valleys before turning eastward at Dubois and heading toward Yellowstone National Park passing Henry's Lake in Island Park. After a meandering route through Yellowstone, the Nez Perce National Historic Trail exits the park near the east entrance and follows the Clarks Fork River towards Billings, Montana. At Laurel the trail moves north straight toward Canada.

In 1941 and 1942 work was started on a large (35,000 men) Mountain Training camp by the US Army across from the Valley View Gas Station on the east end of Henry's Lake along US20. There are still concrete remains of the initial camp. Before it got really started, the army canceled it and tore down the existing structures. Read an interesting account of why it was started and then almost mysteriously stopped.

The Nature Conservancy (TNC) has a large holding in and adjacent to the city known as The Flat Ranch, which has a visitor center that hosts educational programs about the area’s natural resources. Also of note is that several ranches in the Henry’s Lake area are part of a TNC project, known as the Henry’s Lake Ranchland Project, that has placed valuable ranch land and riparian habitat in conservation easements to preserve open space from development. Included is the Meadow Vue ranch adjacent to RedRock RV park.

Geology buffs and rockhounds also love Island Park because it lies in an ancient volcanic caldera, with many areas of volcanic rock in clear view. Garnet Hill, a hill in the city near Henry’s Lake, is a favorite spot for rockhounds seeking garnets, especially during the spring run-off period. Island Park is a wonderful place to raise kids, run a business that serves thousands of travelers from all over the world every year, or have a second home to enjoy the outdoors.

In 1924, the Henry’s Lake Dam was completed, introducing irrigation water storage for lower Snake River Valley farmers. In 1933, the power plant on the Buffalo River, built by the CCC, introduced hydroelectric power to an area that had relied upon gas generators. In 1935, the Island Park Dam was completed.

The Mack’s Inn Resort area dates back to the beginning of the 20th century. The resort was established at its current location around 1914-1916 by William H. Mack. During the summer months, the Mack family focused on construction and expansion. Their winters were spent in the Snake River Valley planning for the next season.

For 75 years, Mack’s Inn continued to grow with more buildings, cabins and units. Then in 1989, a tragic fire destroyed the Mack’s Inn Lodge, a beloved landmark. The loss of the lodge was a great disappointment for the local residents and vacationers.

Mack's Inn was purchased in 2018 by Ensign Hospitality, LLC in hopes to provide a new experience to travelers seeking an adventure. The goal is to build a new hotel that will blend in with the surroundings of Island Park, while still providing the resort experience Mack's Inn is known for.

The Mack's Inn RV Park was renamed Yellowstone RV Park of Mack's Inn when it was purchased in 2018 by Parks Resort, LLC and completely upgraded with new electrical and water faucets to permit big rigs and overnight guests.

Island Park remains a destination in itself, with world class fishing almost year round, scenic wonders like Mesa Falls, Henry's Fork of the Snake River and Sawtelle Peak (from the top), hundreds of miles of ATV and Snowmobile trails, and mammals, birds and wildflowers galore for photographers and naturalists to enjoy.