United States of America (USA) is one of the largest countries with many natural wonders. Here, the ranking based on the total height of the waterfalls including drops, and the size including the total volume of water. Many largest and tallest waterfalls are found in the USA, and they also a popular tourist destination in the country. While all of the waterfalls are unique in its kind it is hard to judge which waterfalls are best and beautiful. This is a list of waterfalls in the USA by height and total volume (flow rate) and many are officially measured.
Tallest waterfalls in America (by overall Height)
Tallest waterfalls are measured by overall height including total drops.
1. Oloupena Falls (unconfirmed)
Total Height: 2,953 ft (900 m)
State: Hawaii
Oloupena or Olo’upena falls is the tallest waterfalls in the US and unofficially reported as the fourth tallest in the world. It is located in Molokai, the north-eastern part of Hawaiian Island. It is Tiered type waterfalls and formed on a short (seasonal stream).

2. Pu’uka’oku Falls (unconfirmed)
Total Height: 2,756 ft (840 m)
State: Hawaii
Also known as Puukaoku Falls, located in Molokai in Hawaii. It is the 2nd highest in the US and 8th tallest in the World. It is just 500 m east from Oloupena falls and is thin and deeply etched.

3. Waihilau Falls
Total Height: 2,600 ft (792 m)
State: Hawaii
It is thirteenth-highest waterfall by overall height and second tallest by the longest single drop in the world. It is Horsetail type waterfall on Waihilau River, located in Waimanu Valley in Hawaii. It has only one single longest drop of 792 m.

4. Colonial Creek Falls
Total Height: 2,568 ft (783 m)
State: Washington
It is also known as Hiavaty falls, located in North Cascades National Park of Washington. Colonial Creek is the source of the waterfall with a total of 14 separate drops with an average incline of 65 degrees. Colonial Creek is a modestly sized stream and will flow consistently all over the year.

5. Johannesburg Falls
Total Height: 2,465 ft (751 m)
State: Washington
Johannesburg falls is the 18th highest falls in the world, has a total of 5 drops and pitch in 59 degrees, 800 feet of single longest drop. This falls located in Skagit County of Washington State. The Glacier is the watercourse of Johannesburg waterfalls. It is best flowing in the month of June to October with an average water volume of 25 cubic feet per second.

6. Yosemite Falls
Total Height: 2,425 ft (739 m)
State: California
Yosemite Falls is located in Mariposa County in California State, also the tallest waterfall in California. It has a total of 6 drops and Avg width of 30 meters with 85 degrees pitch. It is flowing 8 months in the year with an estimated average water volume of 250 Cubic feet per second.

Largest waterfalls in America (by Volume)
Largest waterfalls are measured by Volume (Flow rate in CFS) which including total drops.
1. Niagara Falls
Avg. Volume: 85,000 CFS
Water Course: Niagara River
Niagara falls are the Cataract type of waterfalls and located on the international border between Canada (Ontario) and the United States (New York). Niagara Falls consist of three falls are the Horseshoe Falls (Canada side), the American Falls (US side), and the Bridal veil falls (US side), the horseshoe falls is 2,600 feet wide while the American fall is 1,060 feet wide.

2. Willamette Falls
Avg. Volume: 30,849 CFS
Water Course: Willamette River
It is a natural waterfall located between Oregon City and West Linn, is the largest waterfalls in the Pacific Northwest of America and seventh widest (1,500 feet) in the world. Willamette falls in the shape of Horseshoe and it is 76 feet high.

3. Great Falls
Avg. Volume: 16,750 CFS
Water Course: Potomac River
This is a waterfall located in Montgomery County in Maryland, 15 miles from Washington DC, is one of the major waterfalls in the US. Great fall is also known as ‘Great Falls of the Potomac’, but Great fall is the official name.

4. Kootenai Falls
Avg. Volume: 10,941 CFS
Water Course: Kootenay River
Kootenai waterfall is located in Lincoln country in Montana. At 55 ft height (including tallest single drop 30 feet), and 1,000 ft wide, is one of the widest waterfalls in the US. Kootenai falls also known as Kootenay falls.

5. Sandstone Falls
Avg. Volume: 7,847 CFS
Water Course: New River
Sandstone falls is the largest waterfall on the New River, it is 1500 feet wide (one of the widest falls in the US). The height of the waterfalls is varying from 10 to 25 feet. This waterfall located in West Virginia on New River.

Inundated largest Waterfalls in the US
This waterfall formerly existed, has since been flooded beneath the waters impounded behind a dam.
Celilo Falls
Avg. Volume: 190,000 CFS
Water Course: Columbia River
State: Oregon
Kettle falls
Avg. Volume: 165,340 CFS
Water Course: Columbia River
State: Washington