The Larch Mountain Trailhead includes parking and restrooms to get you started for either a casual hike or ride along logging roads, or a challenging hike or ride that can take you several miles.
The Thrillium Mountain Bike Trail which goes north from the trailhead, is very steep in places. Following the road that goes uphill to the southeast, will take you to the top of Larch Mountain, and connects to more trails to choose. When I visited here a couple months ago, I followed the Cold Creek trail to the north from the summit that was prepared for a mountain bike race later that day. I found some parts of this trail challenging to descend, and impressed that people would actually ride a bike down it. I then connected with the Tarbell Trail, and followed an easy walk along a logging road (Murphy’s to Thrillium Access Route) until I turned onto the Thrillium Mountain Bike Trail and climbed (yes, CLIMBED) up the hill back to the trailhead. While some of these trails offer splendid scenery and views, you might want to leave some of them to the mountain bikes. The loop I walked was about 5-1/2 miles. Enough trails exist in the area to choose pretty much any length of walk you want, including connecting to the 20 mile loop Tarbell Trail.
Trails in this area are well mapped on trailforks.com