Red Ridge is a great ridge hike offering several options and fantastic views. The ridge is between other formidable mountains like Twin Mountain and Mount Perkins. Annie Lake can be seen from the top and the ridge follows along the beautiful Watson River Valley.
Drive south from Whitehorse on the Alaska Highway and turn right at the Carcross Cutoff onto the South Klondike Highway. After about 17 kms turn right onto the Annie Lake Road (which will quickly turn into a dirt road). After about another 17 kms you will reach the north end of Annie Lake. There is a small pullout on the right and a rough trail that leads towards a marsh. Take this road for a little over 8 kms. It is a rough 4x4 road, so if you don't have 4 wheel drive, it is advised that you don't drive too far up this road. You will cross 2 small creeks on the road and eventually follow on the side of a steep slope before reaching a clearing where you can park and turn around. At this clearing the road continues through the valley, while a wide exploration trail leads up to the ridge on the right - this is the trailhead.
From the trailhead, the exploration road leads up the ridge to a small saddle (~2 km). From the saddle there is the option to continue following the road to the right, which leads up to the east summit, or to turn left (west) to follow the ridge trail described here. The east summit provides a nice side trip or a shorter day trip for great views of Annie Lake, and is about 1 km to the top (one way).
To continue along the main ridge that heads west, pick up a faint animal trail near the top of the saddle that traverses along the left slope of the ridge. This will allow you to avoid some bushwaking, at least for the first part of the hike. It is sometimes hard to keep to a main trail, but the ridge is open enough to find your own route as you try to make your way up to the first peak of the ridge. From this peak you'll get a fantastic view to the west and it will now be easy walking along the rocky, red ridge.
It is about 4.5 km to then end of the ridge from the saddle, with a bit of up and down. You'll get great views into the Watson River valley on the right, and as you get further along the ridge, views of the Thompson Creek valley on the left open up as well.
Eventually the ridge levels out into a flat plateau where the trail disappears. You now have the option of either returning the way you came (which would involve a bit of ascent back up to the peaks of the ridge) or to continue along the plateau and loop down to the valley and follow a road back to the parking area.
For the loop, start your descent down the end of the ridge and try to pick up a rough road which switchbacks down the slope towards the left. This rough road meets up with a better exploration road which leads back to the parking area (just keep to the left). It will be about a 3.8 km hike on the road back to the trailhead.
The winter trail is the same as the summer trail, but you will have to walk or ski the 8 km road instead of driving it. The road is often packed down by snowmobiles and dog-sleds. Once at the summer trailhead and parking area, the road up to the top of the ridge is steeper and the snow can get deep, so make sure to take turns breaking trail. It would make for a very long day if you attempted to hike the full ridge loop in the winter. You may only have enough time (and energy) to get to the ridge top and look over the other side before having to return.
Snowshoeing - Snowshoes aren't required to walk the road or the ridge top, but are neccessary for walking up to the ridge top from the summer parking area. Because you have to walk the road in the winter and break through deep snow, you can expect the trip to take 9 hours just to the ridge top and back. Make sure to take headlamps in case you get caught in the darkness.
Nordic Ski Touring - The road is perfect for ski touring because it isn't too steep. Skiing would make the way out much quicker than snowshoeing. It may be more difficult to ski up to the ridge top from the summer parking area, so you may want to bring snowshoes for this section unless you think you can stay afloat well enough in the deeper snow.