Check out REI almost all of their gear is good. 1 C note is not much of a budget for down bags but will get you a decent synthetic one. Also check out Sierra Trading Post for some good deals, stay with the name brands as they have a range of quality. This one fits the bill: https://www.sierra.com/kelty-20-f-tuck-ex-thermapro-sleeping-bag-mummy

Bags I have owned or used and liked were: Sierra, North Face, Marmot, REI, Jacks Bags, Kelty, Big Agnes and some others I don't recall. I have one that is forty years old with lots of duck tape patches but still good. All the synthetic bags didn't last half as long. Get a tall one and if you are not used to a Mummy get one with a box foot to it, a semi mummy.

Get one rated for three season use as I have had fairly heavy snows in Yellowstone even during the summer. Also get a self inflating foam mattress like a Thermo-Rest, they really make a difference.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli