The heat made the rock more elastic, and the pressure caused the rocks to be folded, faulted, and squeezed upward, forming the high peaks and structures seen today. Because the rock was mainly quartzite and was more elastic from the heat, it had the strength to prevent it from collapsing as it was pushed upwards. The peaks all border the MacBeth Icefield and the Icefield itself is the keystone of the group, and quite large for this region. The neve proper of the Icefield is nearly level and sits at an average elevation of 8500' (2590m) with the summits rising roughly 1000' above that. The neve proper is approximately 4.6 km long and averages 1.5 km wide. The rock quality in the group itself is variable and consists mainly of friable sediments which range from reasonably firm to horribly loose, however portions of most of the ascents are partly on snow.
History: The First Nations may have been the first too see the peaks of group above Glacier Creek. In their attempts to find a route from the Kootenay Valley to the Columbia Valley they may have attempted to go up Glacier Creek but there is no formal record of this.
The first White Man to see the group was most likely the climber E.W. Harnden who in August of 1911 made the first ascent of Mount Monica. The summit would have afforded him and his party of spectacular views of the east aspect of the group, portions of the Icefield, and tributary glaciers which drain the icefield to the east into Glacier Creek North Fork.
Before the construction of the Glacier Creek FSR, the approach was long, starting at Starbird Pass and requiring a high level traverse from there to the NE end of the group and icefield. In 1960 A. Maki and R.C. West were the first to make this traverse all the way from Starbird Pass to the NE end of the icefield. During their 4 day foray (CAJ 44-37) they ascended Mount Macduff and Mount MacBeth becoming the first recorded climbers to ascend peaks in the group. The first recorded ascents of Mounts Banquo and Fleance were not made until 1969, and the first recorded ascent of Mount Lady MacBeth was not until 1972. Since the construction of the Glacier Creek FSR the entire group can easily be accessed from the Glacier Creek drainage, and there is an official Ministry of Forests trail that provides access to the SW end of the Icefield. It is officially known as the MacBeth Icefield trail.