The weight and density of tamarack (or larch as it's called in much of the western states) depends on where it comes from in the tree. Once upon a time I owned 40 acres outside Whitefish, MT that had some big larches growing on it. They were dwarfed by the 5' dbh stumps that were on on the property. The stumps were almost head-high. The loggers (early 1900s) "high-stumped" larches because that section of the tree was so heavy that they would cause the entire log to sink when floated into Flathead Lake. They were called "deadheads." I'm told there's a company that salvages these old giants in the lake. Can't help but think there's some outstanding shaft material there. I wonder about the stumps, too. Larch is extremely decay resistant and the stumps I tested were as solid as they were 100 years ago. If the wood grain isn't wild (as it often is in stumps), that could be some super-heavy shaft material.