Kautilya's Arthashastra 2.2.7

2.2.7

nāgavanādhyakṣaḥ pārvataṃ nādeyaṃ sārasamānūpaṃ ca nāgavanaṃ viditaparyantapraveśaniṣkāsaṃ nāgavanapālaiḥ pālayet //

The superintendent of forests with his retinue of forest guards shall not only maintain the up-keep of the forests, but also acquaint himself with all passages for entrance into, or exit from such of them as are mountainous or boggy or contain rivers or lakes.