Sammakkosuo nature trail in Pudasjärvi commune in northern Finland takes from the parking lot to a day hut and the adjacent bird watching tower.
The trail is in the northern part of the Olvassuo nature reserve. Olvassuo is known for its extensive swamp complex. Apart from being a strict nature reserve, it is also a Ramsar wetland site.
Sammakkosuo parking lot can be accessed by taking a 12 km stretch of dirt road from the Oulu-Kuusamo highway. The access road is in a fairly good condition (2025).