Valmiki Ramayana Aranya Kanda Sarga 7 Shloka 2
Original Shlokaस गत्वा दीर्घमध्वानं नदीस्तीर्त्वा बहूदकाः। ददर्श विमलं शैलं महामेघमिवोन्नतम्।।3.7.2।।
1 source checked for this shloka
सः he (Rama), दीर्घम् long, अध्वानम् distance, गत्वा went, बहूदकाः with plenty of water, नदी river, तीर्त्वा after crossing, महामेघमिव like a huge cloud, उन्नतम् lobty, विमलम् pure, शैलम् mountain, ददर्श saw.
After covering a long distance and crossing the river (Ganga) with plenty of water, Rama saw a huge mountain looking like a lofty cloud.