Carmacks was also known as Tantalus. This area was an important part of the Yukon River route from Whitehorse to Dawson City. Because summer and winter travel routes were not the same, some detachments were closed seasonally. The river side detachments were open in summer and in winter their officers moved to detachments along the trail. Many of the buildings were moved as the detachments had to be relocated to accommodate new transportation methods.
In 1902, the Tantalus detachment had 1 staff sergeant, 3 constables and 3 horses stationed at the post. In 1902, the Tantalus Detachment had lost about 32 feet of frontage in the past two years and it was thought it would be uninhabitable in the spring of 1903. A new site was chosen on what is known as Carmack's flat. The ground was surveyed and cleared, the different buildings staked out for completion in the spring; a cellar under the barrack room excavated and cribbed, garden plot 40 x 54 ploughed, fence posts put in, latrine excavated, sills and sleepers of the barrack room laid and everything in place to construct the building before opening of navigation next year. (North-West Mounted Police Annual Report. Sessional Paper No. 28. 1903:35, 39, 43.)
In 1907, the detachment at Tantalus might well be withdrawn for the coal mines have closed down for the winter, but I do not care to withdraw all the men from the Dawson Whitehorse trail as gold is shipped out by the stages during the winter. (Royal Northwest Mounted Police Annual Report. Sessional Paper No. 28. 1908:11.)
In 1908, the constable at Tantalus was agent of the Crown Timber and Land Agent until the post was withdrawn in August. The constable stationed at Tantalus took his discharge and there was no one to take his place so the detachment was closed. Commissioner Wood reported that there should be police stationed at least four points on the river: Hootalinqua, Tantalus, Selkirk, and Stewart. They are necessary to protect and regulate the small-boat travellers in the early spring. 300 small boats, containing 1,367 persons came down the river this spring. An enormous amount of damage was done by fires started by campers. The government telegraph lines and bridges, cribbings, etc on the government road suffered great damage, to say nothing of thousands of cords of timber and firewood destroyed. (Royal Northwest Mounted Police Annual Report. Sessional Paper No. 28. 1909:199, 205.)
In 1909, there were so many men (over 800) coming down the river in small boats from the middle of May to the end of June, that constables were stationed at Hootalinqua, Tantalus and Stewart. (Royal Northwest Mounted Police Annual Report. Sessional Paper No. 28. 1910:212. )
Carmacks retains an RCMP detachment today.