Pear trees

The near by park had 2 larg , 30" plus diameters pear trees, with delicious fruits every fall, and  very close to being the largest trees in the area which included some large sycamores.  The only way we could get any was by throwing sticks and such to knock one pear down. It wasn't easy.  
   AI says the only pear growing close to that size is an invasive species that has pitiful fruits. This was in central Indiana, can anyone identify the trees?

I've been around Indiana for quite a while and I remember when we lived in town a tree that might have been that big. The pears were fantastic, us kids could climb parts of it, we used rocks, sticks and fishing poles to knock them down. Lots just fell and many rotted, the wasps loved them. A little kid could get quite sleepy sucking the juice out of the partly rotted ones, it was so good! There is a similar tree by and old church not far from me now, but it isn't that big. I don't think I ever knew a name for them.

Ai is not to be trusted

I'm pretty sure most  pears get big unless they are grown on dwarfing rootstock.
Even then, they get 30 foot tall if left to their own devices,at least in my experience.

There are even some pear tree selections that produce extra tall, strait trunks, specifically for lumber.