What railroad served Island Park, Idaho?

The Oregon Short Line Railroad — a subsidiary of E.H. Harriman's Union Pacific — built a branch line through Island Park, completing the route to West Yellowstone, Montana in 1907 and beginning regular passenger service in 1908.

Why was West Yellowstone built where it is?

West Yellowstone was platted in 1908 specifically as the terminus of the Oregon Short Line's Yellowstone Branch. The Union Pacific Depot still stands at the heart of town.

Is the Island Park railroad still in use?

No. Passenger service ended in 1960 and the Yellowstone Branch was eventually abandoned. Portions of the right-of-way are visible from US-20 between Ashton, Idaho and West Yellowstone.

Mack's Inn: A Henry's Fork Resort Community Since 1922

8 min read · Updated June 2026

Origins: A Crossroads on the Henry's Fork

Long before there was a town, the spot now called Mack's Inn was a natural river crossing. The Henry's Fork — fed by the enormous outflow of Big Springs just five miles east — slows into a broad channel that early trappers, stagecoach drivers, and Shoshone and Nimíipuu travelers all used to ford on their way north to Yellowstone country.

By the 1910s the wagon route had been graded into a passable summer road, and in 1922 A.S. "Mack" McCrea picked the river bend as the site for a small log lodge — six cabins, a store, and a place to feed the steady trickle of anglers and Yellowstone-bound tourists.

The Mack Family & the First Lodge

The McCrea family ran the lodge as a true family business — wives, sons, and daughters running the kitchen, the cabin court, and a small dock where guests rented rowboats to drift the slow water back toward Big Springs. By the early 1930s the lodge had been expanded, a riverside dining room added, and the property had picked up the name everyone still uses: Mack's Inn.

The lodge sat on the same evolving US-191/US-20 corridor that — see our article on Island Park's railroad history — was replacing the Oregon Short Line as the main way Americans reached Yellowstone.

Rail-Era & Highway-Era Growth

The postwar boom transformed Mack's Inn from a single lodge into a small resort community. New cabin courts opened along the highway, the float-tubing tradition on the Henry's Fork took root, and the community absorbed traffic flowing to and from the Railroad Ranch downstream.

By the late 1960s, Mack's Inn had become a touchstone for repeat Idaho-side Yellowstone visitors — the place where families measured childhood vacations by the height of the rope swing on the river bend.

The Resort & Community Today

Mack's Inn is now a small, working resort community on US-20, anchored by the Mack's Inn Resort lodge and restaurant, a marina renting tubes and kayaks, and the long-running Mack's Inn Dinner Theatre. In winter the area is a snowmobile hub plugged directly into Island Park's groomed trail network — see winter activities.

For trip planning, see our trip planning hub and Top Things to Do in Island Park.

What to See in Mack's Inn

Mack's Inn Resort & Dinner Theatre

The historic core; check current season schedule before booking.

Henry's Fork Tube Float

Gentle 2-hour drift from Mack's Inn back to upstream landings; rentals on-site.

Big Springs & Johnny Sack Cabin

Five-minute drive east; see Johnny Sack Cabin.

Upper Coffee Pot Campground & Rapids

Short hike to the river's whitewater stretch.

Big Springs Loop Road

Scenic backcountry route popular with cyclists and snowmobilers.

Founding dates and family history draw on local Island Park historical society records and may vary slightly between published sources.

Stay 5 Minutes from Big Springs & Mack's Inn

Lodgepole Pines Retreat puts you minutes from the Henry's Fork tube float, Big Springs, and Johnny Sack Cabin. Sleeps 12 — book direct and save up to 10%.

Book Your Stay — Save 10%