Here is how it went:
1902 (and earlier): Roosevelt reads Powell and others; he becomes excited about the Grand Canyon.
1903: TR visits the Canyon, and explicitly calls for GCNP. He orders Interior to move along on readying Park bill.
1904: he is re-elected.
1905: he orders Interior, USGS & GLO, to bring forward the bill, now that the work on surveying and Santa Fe exchange is done. The bill is introduced along with Arizona statehood.
1906-7: Congressional fight led by Rep. Lacey. Passed as tribute to TR's great conservationist leadership.
Or if you are dubious, let there be a big fight, and with Lacey gone after 1906, maybe no bill; but the issues would have been joined a decade earlier.
This, of course, is not what happened. Why not? Why didn't Roosevelt speak and act on this enthusiasm of his? Why did he not even start the administrative machinery working in Interior?
And specifically, what is there to learn from Brinkley (=B) on the mystery of Roosevelt and the missing Grand Canyon National Park? (Brinkley, Douglas, The Wilderness Warrior Theodore Roosevelt and the Crusade for America, 2009)