When I was in Washington last week, I found out it will be some months before the Elsie and Perrinton topographic sheets are photographed so I copied essential data that I thought useful for the lake features. I inclose the map with the data; please return it after you are done. You will see my notations on either side of each sheet. The Elsie-Perrinton area falls within the Clinton County area. I traced the 700' contour as there is a beach along it which causes it to make some loops; is this the Warren or the lowest Arkona? I also took various altitudes which may be useful if we visit there. I also traced the 725' contour as it is along or near the highest Arkona, and it reaches 730' in southern Brady Tp (on Chesaning sheet). It may be as low as 715-720' at the outlet head near Maple Rapids and I suspect the top of the island that stands in the outlet W of Maple Rapids is about at the level of the outlet at time of 1st Arkona Beach. It is 720' on the E end and above 715' on the W end. The Imlay Outlet bed is 715' a mile SE of Maple Rapids so the Grand River outlet cannot have been higher and the highest Arkona isn't likely to be more than 720'. Perhaps the 1st Lake Saginaw lowered the outlet to less than 715' at Maple Rapids. The 1st Saginaw may be 720' there and the 1st Arkona at ~710', as they are about 8-10' apart. Near Henderson, the 1st Saginaw is 735-737' and the 1st Arkona is 725-728'. Your note may be able to clear this up. If the 1st Arkona is down to 710' at Maple Rapids the isobase for 0 uplift must pass through or near the outlet head at Maple Rapids. The moraine running through Eureka W to Maple Rapids blocks the N end of a broad valley with a northward descent from the Imlay Outlet to Maple River. The valley is about 715' where it branches from the Imlay Outlet in Sec. 24 Essex but in Sec. 19 Greenbush Tp. it drops below 700'. These features suggest that the waters of the Imlay Outlet turned N into this valley and flowed across wetern Greenbush Tp. before the ice readvanced to form the Eureka-Maple Rapids (Owosso) Moraine. This indicates the Maple Valley in southern Washington Tp. was below 700' and that if it discharged W into the Grand River, the Grand River Outlet was cut well below 700'. You made a suggestion (p.257-8 + fig. 1) that the Owosso Moraine had pushed into the Grand River Outlet beyond the line of an earlier moraine (Flint) , and the features in this valley tend to support your view. I can't find a way to put the outlet head up to 715' at Maple Rapids at the time of 1st Lake Saginaw unless the outlet was graded up to that height by outwash from the Owosso Moraine. You will note I made the Owosso Moraine follw the S side of the Maple River from Eureka W to Maple Rapids; the contours on the mapseem to show a continuous connection. There is a large flat area W of Maple River in DuPlain and E Greenbush Tps. that is low enough to have been carried by the highest Arkona and the 1st Lake Saginaw. Did this plain have a sandy or clay soil? I wonder if the Owosso Moraine did not run to DuPlain and then NW to Eureka. There is an area 725-735' in SE Greenbush that seems to have several channels across it opening W to the Imlay Outlet which is below 725'. I wonder if the ice edge rested on the NE edge of the tract in E part of Secs. 25 & 36 as late as the Owosso Moraine, or is it part of the Flint Moraine? The 2nd Arkona beach shows nicely on the Elsie sheet from Chapin Tp to Eureka and descends from 717' to ~710'. Some work with a hand level would show the amount of uplift here. The very low rate of descent of the Maple River from 650' to 645' over 11 miles is surprising so there is a question of when the uplift began. I hardly think Maple River ever discharged to Saginaw Bay. The divide in central Elba Twp is a bowldery strip and may be a waterlaid part of the Henderson Moraine with a possible outer border that is a long swamp in the next Twp. The map features suggest to me that perhaps Lake Wayne discharged through the Grand River outlet; the sand ridges may mark the Wayne beach at 675' here. If so, the sand ridges may indicate a westward discharge to Maple River. But the problem is that if Lake Wayne discharged W at a low altitude, how could the Warren stage follow it and reach an altitude 20-25' higher? I had a long discussion with David White about the NY work, and he and Alden sent a statement to Clarke, suggesting that the work start this year, and continue next year if the war and allotments permit. White thinks to allot me $150-200 for conference, etc. I need a few days with Weidman in WI and a possible visit with WA Johnston in Manitoba to see his evidence for recurrence in the Red River Basin. Have you written to Tyrrell about the outlet of Lake Agassiz to the Arctic? He could probably give you better information than anyone about the region between Agassiz and the Mackenzie River. Rec'd a letter from Sardeson saying that our bulletin on NE MN was delievered May 23rd, and he has a copy. I have not rec'd mine yet. I will ask that a copy be sent to you.