Kāmyavana is mentioned in the Ādi-varāha Purāṇa:

caturthaṁ kāmyaka-vanaṁ vanānāṁ vanam uttamam
tatra gatvā naro devi mama loke mahīyate

Lord Śiva said, “The best of all forests is the fourth of these, named Kāmyaka. O goddess Devī, any person who goes there is eligible to enjoy the glories of my abode.”

In the Bhakti-ratnākara (Fifth Wave) it is also said:

ei kāmyavane kṛṣṇa-līlā manohara
karibe darśana sthāna kuṇḍa bahutara
kāmyavane yata tīrtha lekhā nāhi tāra

“In this Kāmyavana, Kṛṣṇa performed enchanting pastimes. Here you will be able to take darśana of many ponds and other transcendental spots. I cannot even describe in writing all the sacred tīrthas found at Kāmyavana.”