Shiva Purana
गिरीनतीत्य सकलांश्चतुर्द्दिक्षु महांबुधिम् ॥ सा ययौ प्रयता सूता गंगा त्रिपथगामिनी ॥ ३२ ॥
Thus the holy river Gaṅgā flowing along three paths, flows into the great ocean in the four quarters after crossing all the mountains.
english translation
girInatItya sakalAMzcaturddikSu mahAMbudhim ॥ sA yayau prayatA sUtA gaMgA tripathagAminI ॥ 32 ॥
hk transliteration by Sanscript