Further to my previous question: what tree is this
The tree in my backyard has pink flowers in the spring (around April/May), small little bunches of tiny petals, the leaves are small and oval in shape and the red berries (in the fall - September to November) are in bunches of two to four. What type of tree is this?
Cheyenne, if the tree is crabapple, the apples are not poisonous...very sour (tart), but not poisonous.
My guess would be a crabapple. Without size information and/or pictures, it's strictly a guess. Hopefully, this article will help: https://extension.colostate.edu/pubs/garden/07424.html
If it doesn't help, consider taking leaf samples and berry samples to your local agricultural extension office for identification.