There must be some good places and trails off the Forestry Trunk road around Calgary... I'd be looking for some places to spend the night as well.. as far away from the public campgrounds as possible.
I'm ashamed to say I haven't explored it nearly enough.
I'm a complete newbie to off roading but thankfully, there are many Jeep enthusiast groups out there. One of them is holding a 4x4 off road course for beginners in June so I promptly signed up for that.
The Prairie Creek area southwest of Rocky Mountain House offers experienced off-roaders a decent challenge. The informal trails throughout Prairie Creek are difficult, but they are perfectly suited to both off-road vehicles and snowmobiles. While you pretty much have the run of the trails, keep in mind that off-roading in the campsites is prohibited. Allow at least a full day for your adventure, or plan on setting up camp at the campground, because you'll face plenty of sheer drop-offs, water crossings, and other difficulties that demand plenty of time.
Lost Knife Trail
Off-roading skills not yet up to snuff for an option such as Prairie Creek? Head to Lost Knife Trail instead. With a route perfect for many beginners, you can easily access this off-road trail from Highway 40, just north of Waiparous Village. Offering 20 kilometers of trails, Lost Knife is an ideal place to test your budding skills, although it is considered a moderately difficult trail. Despite the excessive dust you're sure to stir up, the trail is easy to follow, making it a great option for all experience levels.
Ruby Falls
Located about four and a half hours southwest of Edmonton, Ruby Trails offers something for every type of off-roader. The trail peaks at 1,929 meters and features various water crossings, not to mention a variety of rock, gravel, mud, and grass terrain. Many off-roaders hitting Ruby Falls also take on the adjacent Southesk Trail, but plan to reserve an entire day if you wish to complete both trails simultaneously.
Top of the World
A relatively short trail, the Top of the World trail at McLean Creek, just west of Calgary, is an off-roader's dream. It offers a steep climb and heart-pounding drop that sets it apart from all other trails. With the significant climb in elevation, you also get the benefit of experiencing some spectacular views before heading back down. This trail puts even the most experienced off-roader's skills to the test and isn't for the faint of heart. Be sure you're ready physically and mentally before tackling the Top of the World.
Timeu Creek OHV Recreation Area
Known locally as Vega, the Timeu Creek OHV Recreation Area is located 40 kilometers north of Barrhead and is one of Northern Alberta's largest off-highway vehicle (OHV) parks. It offers two campsites with washrooms that serve as staging areas, making it a great option if you're planning a full weekend to go off-roading. Timeu Creek is a remote area, so conditions can vary significantly depending on the season. This includes wet and rainy conditions during the spring and moderate snow levels from November to April. Therefore, dress appropriately and bring your GPS to find directions if you aren't familiar with the area. Two-way radios are also recommended, as cell coverage is practically nonexistent.
for anyone in Ontario, please consider joining the OF4WD for trails, status and conditions. they have a great trail index of totally legal trails, (and also list the no go zones too), albeit quite small at the moment, until more ontarians can add others.
most frequented trails in ontario are in the Minden/Bobcaygeon area, but there is also Ardbeg/Parry Sound area as well.
Sudbury has some nice trails too, but not yet added to the trail index.