Does anyone know of any resources discussing Lewis as a hiker/biker?

Or a collection/list of his hikes or bike rides?

In Surprised by Joy Lewis suggests that hiking and biking - the movement through landscapes or “an appreciation of external nature” - is of utmost importance – on par with reading.  

Of the landscape in Surrey he writes “… to walk in it daily gave one the same sort of pleasure that there is in the labyrinthine complexity of Malory or the Faerie Queene”.  He also states that while studying with Knock he developed a life-long habit of walking for two hours every day.

Surprised by Joy contains a lot of commentary on specific named landscapes. From correspondence we know some specifics walks he took – for example with Warnie from Chepstow up the Wye River valley (1/1/31). 

I am planning a possible trip to some of these landscapes.