Length of route: 19 km

Course of route: Semily – Bítouchov – údolí Jizery – Podspálov – Morava – Kamenického stezka – Semily

Description of route: An original nature trail of the Jizera Valley state nature reservation, opened in October 1983. This trail leads collaterally with the red marked tourist trail and is passable in both directions. The information panels located along its course provide visitors with basic information about the reservation's natural wealth and history.

9 October 2008 saw the ceremonial opening of a new nature trail leading side by side with the Rieger Trail between Semily and Spálov. This new trail features 15 stops dedicated to the preservation of the environment, fauna, flora, geology, tourism and objects of technical interest located in the valley. The information panels with texts in Czech and English also offer illustrations and photographs.

One of the trail's most intriguing places is a 77-metre suspension gallery hovering 5.5 m above the original level of the river.

The hydroelectric power plant in Spálov is another exceptional building. The water is led to the turbine through a 1300-metre long duct hollowed in the rock.

The trail also winds past several lookouts offering breathtaking views of the Jizera River and its valley.