Upper Mesa Falls is a further km. north along Hwy 47 from Lower Falls and well indicated. The view here is much better than at Lower Falls due to walkways and boardwalks. You can get much closer to the Falls and a lot of different angles. The Upper Falls here are approx. 35 metres high and 65 metres wide.
Only drawback, this is a fee area and costs 5$ per vehicle, but certainly well worth it. There is an interptretive centre at Big Falls Inn, on the parking lot, but only open during the Spring and Summer.
Apparently from here there is a track to Lower Falls for a close-up view but I never saw it.
Driving up from Ashton, it is about 22 kms on Hwy 47 to the turn-off for the Lower Falls. It is an easy walk to the Overlook where the Henry fork of the Snake River rushes over the rim, a drop of some 20 odd metres.
The rock that the falls are constantly eroding is rhyolitic bedrock which in non-geology terms equals packed volcanic ash deposited 1.3 million ago. There is a visitor’s center and interpretive center that was built between 1912 and 1916 by the Mesa Power Company with plans to harness the Falls for electricity but thankfully those plans failed. It is of course closed in the winter and is located near the top of the falls.
Unlike nearly all of the large volume waterfalls in Idaho like, Shosone Falls for example, this waterfall is NOT affected by dams. The result is that this Waterfall runs in its fairly natural state through most of the year.
Henrys Fork-also called the Henry’s Fork of the Snake River-is a beautiful and scenic river that winds through the Targhee National Forrest in the Ashton Ranger District nearly 110 miles (177km) from its source into the Snake River. The canyon and geologic formations uncovered are interesting but the scenic forest atmosphere is what sets this area apart from the surrounding area in Idaho.
In late summer irrigation diversions from its source Henrys Lake may greatly reduce the volume of water. Fishing should be possible from areas beneath the waterfalls and the town of Warm River seems to prove that.