Book Three of the Klondike Mystery Series by Vicki Delany!
In the summer of 1897, Fiona MacGillivray and her eleven year-old son, Angus, arrive in Vancouver in time to hear the news gold discovered in the Klondike! Fiona immediately sets off for Skagway, Alaska, intent on opening a theatre. After one encounter with infamous gangster Soapy Smith and his henchman Paul Sheridan, she decides to pursue her ambitions on the other side of the border in Dawson City. As a dying man breathes his last, he passes on to Sheridan a map pointing due north to the fabled Gold Mountain, where hills of gold keep the heat from hot springs contained in a valley as warm as California.
Sheridan is determined to become the king of Gold Mountain and to marry Fiona and make her his queen. Fiona, of course, wants no part of these mad plans. When Sheridan refuses to take no for an answer, Fiona must rely on Corporal Sterling of the North-West Mounted Police, young Angus, and a headstrong assortment of townsfolk to help thwart his scheme.
If you loved Gold Mountain, check out the fourth book of the series, Gold Web.