A must-see through the Humber Valley is the Humber Arboretum. It's a really beautiful trek in Toronto’s west end. It covers over 250 acres of botanical gardens and natural, wilder areas that surround the West Humber River.
The Arboretum is located just behind the Humber College North Campus at the intersection of Humberline Drive and Humber College Blvd., so there's lots of parking available. If you'd rather take a bus or go on foot, it might be of interest to note that there is an express bus from Kipling station to the college. Terrific way to get there and save on gas.
Once you arrive, you can choose either to take in the beautiful surroundings of the manicured lawns and flourishing flora at the Botanical Gardens in the Arboretum first, or take a walk through many of the marked nature trails through the Arboretum. I liked the "Meadow Walk" which had 3 separate gates. Others include the "Survival Path", "Boardwalk", "Beech Vista", "Woodland", "Pondview" and "Garden Circle". All these nature trails are encompass the Arboretum and excellent tools for educational purposes as well.
The areas surrounding these paths are filled with meadow flowers and forested areas of over 1700 different species of plants and old and new native trees. The trail paths following out of the Arboretum will take you northwest from this point towards Humberwoods Park in the direction of the Indian Line Campground where you will come across the Claireville Dam & Reservoir, constructed in the aftermath of Hurricane Hazel. 
Further northwest still is the Claireville Conservation Area, which is an 848-acre natural and forested area located on the border of Toronto and Brampton. It is one of the largest tracts of land owned by the Toronto and Region Conservation Authority (TRCA). Not all trails in here are accessible on bike, which is why it is sometimes a good idea to leave your bike at home. 
Claireville is an unsupervised conservation area and supposedly has coyotes and deer (I've only seen a few bird species, though). Although Claireville is a passive conservation area, so it's popular with ‘birders’. So, if your photographic interest is birds, then this is a good find. I will be returning soon before summer's end to take a look at Claireville Conservation Area. Unfortunately I have little patience unless I am alone to take any wildlife photos. If I happen to see something, I will do my best to capture it. Maybe you will have better luck!
For now, I am just content to take pictures of scenic landscapes. If you enjoy looking at the scenes, the photos will take care of themselves.
Happy Trails!
