  We report the discovery of three cool brown dwarfs which fall in the
effective temperature gap between the latest L dwarfs currently known, with no
methane absorption bands in the 1-2.5um range, and the previously known methane
(T) dwarfs, whose spectra are dominated by methane and water. The newly
discovered objects were detected as very red objects in the Sloan Digital Sky
Survey imaging data and have JHK colors between the red L dwarfs and the blue
Gl229B-like T dwarfs. They show both CO and methane absorption in their
near-infrared spectra in addition to water, with weaker methane absorption
features in the H and K bands than those in all other methane dwarfs reported
to date. Due to the presence of methane in these bands, we propose that these
objects are early T dwarfs. The three form part of the brown dwarf spectral
sequence and fill in the large gap in the overall spectral sequence from the
hottest main sequence stars to the coolest methane dwarfs currently known.
