10th 1939-1945 20thcentury avalanches bestfriends birdwatching britishcolumbia california campaigns canada canadiantravelphotography cheeseman children'sfiction colorado cross-countryskiing dating(socialcustoms) downhillskiing economicaspects environmentalaspects europe exercise extremesports fear fiction forceandenergy friction friendship general generalandmiscellaneous goblins guidebooks hathayoga hiking historicsites history historyauroraskiclub inventors italy juvenilefiction maps militarycampaigns minnesota miscellaneous mount mountaineering mountaintroops mountainwarfare nationalparks newzealand physics psychologicalaspects redwing regimentalhistories resorts robots rockslides safetymeasures schools secrets sisters skating skiers skiing skiresorts sledding snakes snowboarding snowshoesandsnowshoeing socialaspects sports switzerland teenagers tourism trainingof travel travelpictorials twincitiesmetropolitanarea twins unitedstates walking wintersports worldwar worldwar(1939-1945)