For those seeking Hokkaido Wilderness:
Domin-No-Mori

A mountainous nature reserve located just beyond Tobetsu Dam, this forested area is home to some amazing Hokkaido wildlife and Hikes. From raccoons, to owls, to foxes, this reserve has everything (a mountain bear was even recently seen on a motion sensing camera in the forest, though they are scared of humans and run away).
There are a range of routes of varying lengths and difficulties, but we especially recommend either enjoying the rivers or doing some mountain hiking. Mt. Pinneshiri and Mt. Machine have especially scenic summits, though the Matchett path between them has been abandoned due to some trail collapses.
Their website: https://dominno-mori.org/
Information Centre Address: 2140-8 Aoyamaoku, Tobetsu, Ishikari District, Hokkaido 061-0254
Mizu to Ikimono no Sato Tu Petto (Tōbetsubuto Wetland Park)

Using the original Ainu word for Tobetsu "Tu Petto," this Wetlands nature reserve is a short drive or a 40-minute cycle from central Tobetsu. It is next to the wide Ishikari River, which is where the original founder of the town, the Samurai Date Kuninao, came in on his boat.
The wildlife you can see here includes rare birds like the Tobetsu owl, as well as stags, raccoons, and foxes. It is a peaceful bit of nature near town great for a relaxed walk. On English language Google Maps, it is more likely to appear under "Tōbetsubuto Wetland Park."
Address: 1887-154 Tobetsubutou, Tobetsu, Ishikari District, Hokkaido 061-3773
For Tobetsu Parks, Picnic Spots and Nature:
Aso Koen

Aso Koen is a lovely park in central Tobetsu town. It is right next to both Tobetsu Shrine and the Date Memorial Museum Complex, a unique local samurai museum. It is a great spot for picnics, with well maintained green grass in the summer, lots of trees for shade and benches, and even a small manmade river for children to play in.
Various memorials are dotted around the park. There is an easily accessible car park, but it is also a 5-10 minute walk from Tobetsu station.
Address: Motomachi, Tobetsu, Ishikari District, Hokkaido 061-0222
Tobetsu River Ryokuchi Park

With a fun outdoor golf range, beautiful flowers in the summer, and plenty of benches, this park along the Tobetsu River is a great place for a walk or bike ride. There are well maintained paths which make for smooth riding. You can't really see the Tobetsu River from the park due to the high reeds and tall grass on the river banks but you can hear all the riverside birdsong.
Address: Kabatocho, Tobetsu, Ishikari District, Hokkaido 061-0218
Next Page: Tobetsu Activities and Experiences