The Blue Envelope (Version 2)

Book 1 of the Adventures for Girls series.
Travelling the snowy wilderness of Western Alaska and Eastern Russia would be challenging for any seasoned adventurer. Go on a journey with our two young ladies, Lucile and Marian, as they attempt to travel across the Bering Strait and back in the most difficult conditions...all with an angry and mysterious miner coming after them! - Summary by Keith Salis