Historical Alder School in Cedar county was just west of current State Rt AA where AA meets M on what is now known as E 1200 Road.

USGS Topo Map Bearcreek has it marked in some of the early 20th century maps. It is about 1/2 mile west of current Alder Church and before you get to Alder Branch which is east of the school location by about a 1/2 mile.

https://missouri.hometownlocator.com/maps/feature-map,ftc,3,fid,746232,n,alder%20school.cfm

If you search for Alder Church in Google maps it will take you to the neighborhood.

John R