Mountain Men were not immune to the constant attention of mosquitoes. From the time of the earliest penetrations of North America, mentions of mosquitoes are common. At numerous points throughout his journal, James Clyman states that the mosquitoes were the worst he has every endured. On the other hand, Osborne Russell never mentions mosquitoes in his journal except once to state that his party had encamped in a favorable valley for three days simply for the reason that there were no mosquitoes.
So how did folks deal with the blood-sucking insects. The most popular way to try and discourage mosquitoes with with smoke: smoke inside the tents, smoke at the portages, smoke in the canoes [Henry, Alexander (the Elder) Travels and Adventures in Canada and the Indian Territories Between the Years 1760 and 1776.] Rudolph Kurz recorded the following in his journal: "Unless one makes a Hades of one's room every evening, with the smoke of sweet sage, one cannot possibly sleep at all. Do these pests prefer the blood of a white, unsmoked body?" But smoke was not always effective. David Thompson [Thompson, David. David Thompson's Narrative, 1784-1812. Glover, Richard (ed.) Champlain Society: Toronto, 1962] was familiar with using smoke to fight off mosquitoes, but felt that 'they can stand more smoke than we can'.
Another way to cope with mosquitoes was to wear protective clothing, either so thick, or tough that they couldn't penetrate it. Again Kurz observes "Mosquitoes are still unendurable; unless a man wears clothes of deerskin they drive him raving mad." Thompson also notes that Hudson's Bay men in 1786 wore 'wide loose caps of cotton with a piece of green bunting [a loosely woven worsted cloth] in the front' to keep mosquitoes from biting them at night; it was too hot to wear the caps in the daytime’. Henry the Younger tried a similar solution in 1806: he made'a kind of mask of thin dressed caribou skin' to keep mosquitoes from his face.
Thompson also describes a unique though not highly successful approach used by a sailor at York Factory: " ...finding swearing of no use, [he] tried what tar could do, and covered his face with it, but the musketoes stuck to it in such numbers as to blind him, and the tickling of their wings was worse than their bites was"
Matt Field traveled the Santa Fe Trail in 1839 and later described his experiences in a series of articles in the New Orleans Picayune. He describes using mosquito netting both at night and during the day when the bugs were bad. (Matt Field on the Santa Fe Trail)