Tolmie Peak is named for William Fraser Tolmie. In August 1833, employed by Hudson's Bay Company and stationed at the newly built Fort Nisqually, Tolmie made the first recorded exploration of the Mount Rainier area. Unable to summit Rainier itself, Tolmie and two Indian guides, Lachalet and Nuckalkat, summited one of the snowy peaks near the Mowich River headwaters. Although Tolmie Peak is named for this event, it is not known exactly which peak was climbed.