yall please help

Veronica went on three hikes. On each hike, she saw the following numbers of animals:
Rivers Edge 3 8

Wooded Marsh 8 24

Canyon Creek 15 35


Veronica tried to order the hikes from least to greatest by number of animals seen per kilometer, but she made a mistake. Here's her work:


least greatest

8 24 35

rivers edge wooded marsh canyon creek

What was Veronica's mistake?