His illness made him leave the capital for good and move to the Crimea.
The years spent in Yalta far from both the artistic milieu of St. Petersburg and the more familiar scenery of central Russia were most fruitful, though very complicated years of Vasilyev's life.
During that period he produced a number of very important paintings, drawings, and sepias, some of these based on entirely new methods.
Simultaneously with the painting of Russian landscapes, Vasilyev began to feel the attraction of Crimean mountain views. Mountains distracted him in his depressed mood brought about by progressing illness, acute feeling of loneliness, and discontent at the futility and vanity around him. For Vasilyev the mountains were the embodiment of beauty and harmony, which he strove to achieve in his paintings. In this concept, though somewhat Utopian, the aesthetic and moral aspects of art are inseparable: «If there is nothing in a picture but this blue air and mountains, absolutely cloudless, and if this all is depicted the way it is in the nature - full of happiness and of nature's infinite triumph and chastity - then a man looking at this picture will put off any evil intention seen now in all its uncovered uggliness.'« These words from Vasilyev's letter to Kramskoy seem to have anticipated his last painting In the Mountains of the Crimea. The letter does not describe the details of the picture, then done in underpaint; actually it is quite different, but in these words the spirit that imbues the picture is expressed.
In spite of the disastrous illness, Vasilyev continued his work on the picture. Almost monochrome, it is striking in its rendering of the solemnity of the mountains with their peaks covered by clouds and the flood of light flowing from the depths of the sky above them. For the first time, probably, the painter's insight into the nature's mystery and his vision of its beauty and harmony materialized and became manifest.
In 1873 Vasilyev completed the painting and had it sent to St. Petersburg for participation in a contest. Kramskoy highly praised its fine technique and romantic spirit.
