"Picturesque," "immense," "fantastic," and "sublime" are a few of the ways early British travellers described the landscape of the Rocky Mountains and the surrounding terrain. As part of a long tradition of British travellers' tales, these tourists—explorers, sportsmen, writers, scientists, artists, missionaries, and merchants—sought ways to describe the vastness and strangeness of the North American landscape to a British audience.

Using their published and unpublished accounts as source material, Mountains So Sublime weaves their observations, their aesthetic, and their 'Britishness' into a unique view of a nearly vanished West. Attempting to make their West real to their readers, these travellers encouraged the growing realization that North American scenery was a unique aspect of the world's natural heritage. Many travellers also sought to convey the changes brought by an onrushing progress.

The British were among those who cautioned against excessive human encroachment on the landscape, demonstrating what might be called "environmental pre-awareness." Today's readers will discover perhaps surprising parallels between modern environmental and conservation issues and the concerns expressed by these early travellers.