Regulator was a sternwheel-driven steamboat built in 1891 which operated on the Columbia River until 1906, when it was destroyed by explosion which killed two of its crew, while on the ways undergoing an overhaul at St. Johns, Oregon.

[1][2][3] The boat was contracted for by the Dalles, Portland and Astoria Navigation Company, popularly known as the Regulator Line, or by its abbreviation, DP&AN.

[4] The first annual meeting of DP&AN subscribers was held on Saturday, April 4, 1891, at 2:00 p.m. at the Board of Trade, in The Dalles, Oregon.

[6] In mid-March, 1891, the DP&AN committee returned to The Dalles, having made arrangements with four shipbuilders to submit, to the company’s first annual meeting, to be held on April 4, sealed bids for a steamboat that would be 160 feet long, 30 foot beam, and 7 foot depth of hold, capable of a speed of 17 to 18 knots.

[6] At the April 4 annual meeting, the committee reported that they had awarded the contract to build the vessel to Paquet & Smith, for the price of $25,000, with directions to construct a sternwheeler at any point between Cascades Locks and The Dalles, to be finished by August 1, 1891.

[7][8] The new steamer, named Regulator, was built in The Dalles, Oregon, on bank of the Columbia River at the foot of Washington Street.

[9] The boat was driven by twin steam engines, horizontally mounted, each with bore of 16 in (406.4 mm) and stroke of 7 ft (2.13 m), producing 300 to 350 total indicated HP.

[9] In mid-July, 1891, the hull was complete, the lower works were nearly done, and the upper cabin (called a "saloon") was shortly to be enclosed.

[11] Regular’s hull was 152 feet long, exclusive of the extension over the stern, called a fantail, on which the sternwheel was mounted.

[15]The trial trip of the Regulator was run on September 10, 1891, with the boat departing from The Dalles at 9:34 a.m., proceeding downstream towards the Cascades, which it reached at 12:04, with landings en route at White Salmon, Stanley Point, Hood River, and Chenowith.

[17] On board were sixty invited guests, mostly stockholders of the company and their wives, as well as the builder, Louis Pacquet, of Portland, Oregon.

[18] Regulator departed the Cascades at 1:24 p.m. and arrived back at The Dalles at the dock at the foot of Court Street at 4:50 p.m.[16] On the morning of the next day, September 11, 1891, the directs of The Dalles, Portland & Astoria Navigation Company held a meeting at the office of contractor Hugh Glenn, and formally accepted the vessel from the builders, Pacquet & Smith.

[24] Reportedly the company had secured 50 empty oil drums, with the plan of shoving them into the sunken hull, displacing the water inside, and floating the steamer so it could be taken downriver to Portland for repair.

[25] On September 2, 1898, the Sarah Dixon was able to tow Regulator into the Cascade Locks, where, on the next day, the boat was laying as if in a drydock.

[27] However, when launching the vessel, a piece of one of the temporary ship ways broke loose and punctured the hull, so that it flooded again once it entered the water, leaving the boat laying over on its side.

[26] The plan in early September was to place 200 empty oil drums into the hold, and thereby float the vessel either to The Dalles or Portland for more through repair.

[28] On the evening of Saturday, February 18, 1899, under 90 pounds steam pressure in the boiler, Regulator was taken on a trial run from The Dalles to Lyle, Oregon.

[29] The trial was satisfactory, and the steamer was ready to be placed into service as soon as painting and some minor improvements could be completed.

[20][31] The cause of the explosion was not immediately known, but appeared to originate with an oil tank on which the two men who were killed, engineer De Monte W. Wade and fireman Merrill B. Stayton, were working.

[31] Engineer Smith saved the life of a watchman, who had been asleep in a cabin on the upper deck, by breaking down the jammed door with a timber.

According to one witness, a carpenter who had been just about to board the vessel when the explosion occurred:The inside of the steamer appeared to be a roaring furnace, and then at once the flames began to break out along the entire upper works[31]There were about six barrels of fuel oil in the forward oil tanks, which held a total of about 78 gallons.