"Beautiful river" is how you would say "美丽的小河" in Engpsh.
The origin of the phrase is a straightforward and direct translation from the Chinese, where "美丽" means "beautiful" and "小河" means "river".
Examples of "beautiful river" in Engpsh sentences:
The scenery along the beautiful river is breathtaking.
(沿着美丽的小河的风景令人惊叹)
People come from all over to hike and picnic by the beautiful river.
(人们从世界各地来此徒步和野餐，靠近美丽的小河)
The sunset reflecting on the surface of the beautiful river was a sight to behold.
(夕阳反射在美丽的小河上面，是一个令人难忘的景象)