When Congress legislated and passed, and the President signed, the Grand Canyon National Park Enlargement Act of 1975, the Park boundary from river mile 164.8 to mile 273.1 was set on the south bank of the Colorado River, as this piece of the official map (113 20 021B, Dec 74, produced by NPS' Denver Service Center) shows.
Note well that the Act set the Park boundary; it did not change the Hualapai boundary, which remained what it had been since the military reservation of 1881. To quote the confirming Executive Order of 4 Jan 1883, that boundary has its
"Beginning at a point on the Colorado River "
and it ends by going
"north 30 miles to the Colorado River, thence along said river to the place of beginning."
Simple, yes? The 1975 Act cleared up the ambiguity in the E.O. by specifying that "on", "to", and "along" the Colorado mean the south bank. It took no Hualapai land.*
There are those who fail to understand. So again: the Act did not set the boundary at the historic high water line, the average high water line, the maximum ever most impressive high water line, the Interior-Department-bureaucrats-say-it-is-the high water line. It set the boundary on the south bank. That is to say, supposing yourself in a boat on the Colorado at mile 205, your boat is floating in the Park. When you land at river left, and your boat grounds out, and you step out onto the beach, you are on the south bank, and you are on the Hualapai Reservation. You do not have to wander around in the bushes seeking the place where water came in 1953 or 1923 or 1883. If you are walking about on the land, you are on Hualapai land. When you step back in your boat, you are once again in the Grand Canyon National Park.
Water = Park. Land on the south or left bank = Hualapai. That is what Senator Goldwater, who fathered the 1975 Act, and Congress wanted to do, and that is what they did.
I have written about this issue in several previous entries: 25, 26 & 27 Sep 2009; 7, 8, & 9 Feb 2010, 5 & 6 Mar 2010, 16 Jul 2010. At some point, it will be fun to tell the story and argue the points of this dispute; it does matter. People should know that land on river left between 164.8 and 273.1 belongs to the Hualapai, and act accordingly. Everyone should know that GCNP has jurisdiction and administers the entire water surface from the Paria to the Grand Wash Cliffs, and NPS should act accordingly. That is what Senator Goldwater, who fathered the 1975 Act, and Congress wanted, and that is what they gave us.
Meanwhile, in my next entry, I will consider a very recent example of the misinformation surrounding this boundary.
*This was unlike the 1964 law setting up Lake Mead National Recreation Area, which took in the northern third of the Reservation if the Hualapai concurred. Of course they never did, yet on many maps (including the official map above) LMNRA still shows -- even on the USGS quads, which is why I spent a few months correcting them earlier this year.