Hassalo was built entirely of wood, driven by a sternwheel which in turn drew its power from twin single-cylinder steam engines, each of 17" bore and 60" stroke.

Before rail lines were built, travellers bound from Portland, Oregon for Idaho or the Inland Empire generally went by way of the Columbia River.

This then required transfer to a portage railroad (first hauled by mules, later by steam engines), which proceeded to the top of the Cascades.

[5] Describing the excursion up river, the Sunday Oregonian wrote: Fully 1500 persons were on the ride up the noble majestic stream was an enchanting one.

Field and marine glasses were in ready demand, and hundreds crowded the decks and admired the grand panorama as it passed swiftly by.

[5]The excursion boats arrived at the Cascades, and the excursionists disembarked on the north, Washington Territory, side.

... [W]ith her sharp glistening prow aimed at the great roaring breach, she shot toward the green rolling masses.

With a full head of steam, the Hassalo entered the upper break in the waters, and here receiving the first impulse of the mighty current, made a plunge that thrilled the crowd as if touched by an electric shock.

Crossing the break the steamer rose pointing her bow upward at a sharp angle, and then blindly plunged downward as if going to the bottom; but she came up with the buoyancy of a cork, and now having committed herself to the mercy of the rapids, flew with the speed of an arrow through and over the surging, boiling waters.Hassalo, with just 15 people on board, passed by the people on the bank in just 30 seconds and disappeared from sight around a bend in the river.

As she ran down the rest of the six-mile (10 km) run, she exchanged whistle blasts with locomotives on the railway tracks besides the river.

Once at the end of the rapids, which she ran in seven minutes, Captain Troup took Hassalo down the Columbia and up the Willamette River to Portland.