Oh this wonderfully delicious place. In terms of food, It is one my all time guilty pleasures. For those who passing through Boulder it’s easy to miss. And parking can sometimes be difficult because of the small amount of spaces. But it is worth every inconvenience. It is situated right above Boulder creek so you can take your meal, eat and enjoy the view. This place has been here since as long as I have been born. If you are looking for an amazing Chicago style dog, you are in the right place. They also serve burgers, and some other items. But I just can’t go there and not grab two delicious dogs. With a great selection of condiments and greasy, heavenly fries, you really can’t go wrong. Unless you drop your bag of fries, which is a travesty. I would know because, I have felt this pain. I almost broke down. And even thought about digging in anyway (well not really but the pain is real). Luckily, returning to Mustard’s and explaining the atrocity I just committed. They hooked me up with a new bag of these delicious fries. The interior of the building is cute and pops with character. It honestly looks like a joint you would stop at in Chicago. I have been to many small place like this in my time living in Chicago. The interior has remained the same since I can remember. Mustard’s is just full of character. This place has been a Boulder staple that reaches back to the earlier days of Boulder, before it became so built up. Whether you are a local or just passing through, this place is a must!

Came in for a true chicago dog and not disappointed. A great snap to the dog, and it's on poppy seed buns. All I miss is henning it served up in a paper bag with greasy fries in the bottom