Hiking
Oastler Lake has no hiking trails but the Seguin Recreational Trail is five km from the park.

Fishing
Summer is the best time to fish for rainbow trout, pike and bass.
More information on fishing.

Canoeing
Massasauga Provincial Park 15 km from Oastler Lake has canoe routes one to seven days long for a range of skill from novice to expert. Canoe rentals are available through Oastler Lake.

Boating
The lake is suitable for boats (including motorboats) less than 20 feet long. There is a boat launch and limited docking facilities.

Swimming
The water is clear and clean off the sandy beach. A buoyed area and change facilities make this ideal for family swimming.

Cycling - Cycling trails are within five km of Oastler Lake.