We sort 4683 molecular clouds between 10 ^ { \circ } < \ell < 65 ^ { \circ } from the Bolocam Galactic Plane Survey based on observational diagnostics of star formation activity : compact 70 \mu m sources , mid-IR color-selected YSOs , H _ { 2 } O and CH _ { 3 } OH masers , and UCHII regions . We also present a combined NH _ { 3 } -derived gas kinetic temperature and H _ { 2 } O maser catalog for 1788 clumps from our own GBT 100m observations and from the literature . We identify a subsample of 2223 ( 47.5 \% ) starless clump candidates , the largest and most robust sample identified from a blind survey to date . Distributions of flux density , flux concentration , solid angle , kinetic temperature , column density , radius , and mass show strong ( > 1 dex ) progressions when sorted by star formation indicator . The median starless clump candidate is marginally sub-virial ( \alpha \sim 0.7 ) with > 75 \% of clumps with known distance being gravitationally bound ( \alpha < 2 ) . These samples show a statistically significant increase in the median clump mass of \Delta M \sim 170 - 370 M _ { \odot } from the starless candidates to clumps associated with protostars . This trend could be due to ( i ) mass growth of the clumps at \dot { M } \sim 200 - 440 Msun Myr ^ { -1 } for an average free-fall 0.8 Myr time-scale , ( ii ) a systematic factor of two increase in dust opacity from starless to protostellar phases , ( iii ) and/or a variation in the ratio of starless to protostellar clump lifetime that scales as \sim M ^ { -0.4 } . By comparing to the observed number of CH _ { 3 } OH maser containing clumps we estimate the phase-lifetime of massive ( M > 10 ^ { 3 } M _ { \odot } ) starless clumps to be 0.37 \pm 0.08 { Myr } ( M / 10 ^ { 3 } { M } _ { \odot } ) ^ { -1 } ; the majority ( M < 450 M _ { \odot } ) have phase-lifetimes longer than their average free-fall time .