Did you know there’s a roughly 10-mile long chunk of rock (peanut shaped) known as Asteroid Eros in a stable orbit between Earth and Mars? We pass it about every seven years, it’s going faster than Mars and slower than earth. There is no apparent danger of running into it, its closest approach to the Sun is more than 15% greater than our orbital distance. It was probably near Mars at some point and got ejected into this odd orbit. There are a few smaller ones in the same range, and others that cross the orbit of Mars but not Earth, such as Hungaria which is a fairly big chunk of rock also. At the other end of the scale there’s an asteroid of considerable size (Chiron) which stays out between Saturn and Uranus most of the time, but crosses Saturn’s orbit once every 50.2 years for several years, and came close to crashing into Saturn in the 17th century.
Slight correction, Eros does briefly cross Mars’ orbit and gets a bit further from the Sun than Mars. It is inclined enough in orbit that it would seldom be ever near Mars.